2014 Eastern Syria offensive

The 2014 Eastern Syria offensive is an ongoing offensive launched by the Islamic State of Iraq and the Levant (ISIS or IS) against government-held military installations in eastern Syria during the Syrian Civil War, after expelling the Syrian rebels from the region. The offensive is considered to be the largest military attack against the Syrian government launched by ISIS since its establishment. It is also considered to be a reaction to Syrian Army military operations against ISIS positions in eastern Syria.

Al-Raqqah, Al-Hasakah and Aleppo assaults
Late in the evening on 23 July, a 640-men strong Islamic State assault force (of which 40 infiltrators) launched an attack on the Division 17 base, north of Ar-Raqqah, from three sides. The attack began with two suicide attacks. Both were thwarted by the defenders before they could reach their targets. However, the explosions did leave 19 soldiers dead. The next day, just hours after the attack on Division 17 started, the ISIS launched an attack on the Regiment 121 base (known as the Melbiya Regiment), south of Al-Hasakah, and the Panorama checkpoint at the southern entrance to the city. According to some reports, militants breached the base and killed General Mozid Salama along with 20 of his men. A Syrian Army official denied this claim. At the same time, four infiltrators disguised as NDF members attacked the Ba'ath party building in Al-Hasakah, killing a high-ranking Ba'ath political leader. The four ISIS infiltrators eventually blew themselves up, killing a total of 12 persons.

During the night of 25 July, a suicide car-bomb was detonated at the Panorama checkpoint, killing five soldiers. Meanwhile, clashes at the southern perimeter of Al-Hasakah city killed three YPG fighters, while 11 Syrian soldiers (including an officer) died while defending the Artillery Regiment 121 base. 17 ISIS fighters were also killed near the base.

On 26 July, ISIS took control of Division 17 after government forces retreated, following two days of fighting. Hundreds of troops retreated from the base towards Brigade 93 and nearby villages. Three groups were pulled out, while one group stayed behind to cover the retreat. One of the retreating groups got ambushed by the ISIS, but two other groups, numbering hundreds of soldiers, reached Brigade 93 that day. 300 other soldiers were still held up in the village of Al Rahyat. 50 soldiers from the ambushed group were captured and summarily executed. Overall, 85 soldiers were killed in the battle for Division 17. The fate of 200 others remained unknown, according to the Syrian Observatory For Human Rights (SOHR). Some of the executed Syrian soldiers were paraded in Ar-Raqqah, where the heads of soldiers were put on poles. 28 ISIS fighters were also killed during the takeover of Division 17.

The same day, ISIS forces penetrated the besieged Kwayres air base, east of Aleppo, and captured parts of the airport campus.

In the evening, it was reported that ISIS managed to capture large parts of Artillery Regiment 121 base, and by the next day, according to SOHR, had fully taken control of the base. However, according to Kurdish sources, government troops recaptured the base after ISIS forces retreated under heavy artillery fire. It was also reported that YPG units seized weaponry from the SAA in Hasakah city, while YPG and pro-government fighters set up joint-patrols in the southern parts of Al-Hasakah to prevent ISIS taking control of the city. According to the state news agency SANA, the military recaptured the Penitentiary center for teenagers, the Martyrs Cemetery and the al-Ahrash area on the southern outskirts of Hasakah.

Meanwhile, dozens of government soldiers, fleeing from the captured Division 17, reached the Al-Thawrah air base, also known as Al-Tabqa. Also during this time, ISIS forces retreated from the Kwayres air base due to heavy shelling.

Army counter-attack
On 31 July, ISIS fighters retreated from the Al Mashtal area towards Mafraq Sediq, 7 kilometers west of Al Hasakah city, because of potential shelling by government forces. Meanwhile, ISIS itself shelled Al Hasakah with mortars, leaving three people dead.

On 1 August, the military counter-attacked and ISIS forces retreated from areas south-east of Al Hasakah city. Government troops captured the villages of Al Homor, Al Slaleyyi, Al Fallaha, Al Ma’ruf and Al Maqbara, eventually reaching the old junction of Al Shaddadi during the advance.

Further ISIS advances
After overnight clashes that started with a triple suicide bombing, on 7 August, ISIS forces captured large parts of the Brigade 93 base. The next day, ISIS was in full control of the base and started preparing to attack Al-Tabqa air base, the last government stronghold in Ar-Raqqah province. In the past, different rebel groups besieged the Tabqa air base at different time periods. On 25 November 2013, they had shot down a government helicopter outside the base, killing all of its crew members.

By this time, the number of confirmed soldiers killed at Division 17 was updated to 105, while another 140 soldiers remained missing. 108 of the missing soldiers arrived at the air base on 14 August.

On 8 August, ISIS repelled a Kurdish and pro-government forces attempt to recapture the Geweran neighbourhood of Hasakah city through the Beiruti bridge.

Battle of Tabqa air base
Around 10 August 2014, ISIS started to continuously attack Tabqa air base.

On 17 August, the Syrian Air Force launched 26 airstrikes on Ar-Raqqah city and around al-Tabqa, killing at least 31 ISIS fighters and wounding dozens. At least 8 civilians were also killed and 10 wounded. At the same time, the Army also launched an equal number of airstrikes in Deir Ez-zor against ISIS positions, bringing the total number of airstrikes to 40. The following day, the Syrian Air Force launched another 20 airstrikes against ISIS positions, one of which destroyed the Raqqa city water plant, cutting off water supply to the city. According to Kuwaiti reporter Elijah J. Magnier, the Syrian Air Force used guided missiles following U.S. intel on ISIS gatherings. According to an anonymous source, the U.S. and an unidentified Western country provided the Syrian military with lists of ISIS targets acquired through drone intelligence.

Meanwhile, the Army sent reinforcements to Tabqa air base and strengthened its fortifications inside the base. It also supplied its garrison with large quantities of ammunition and food.

On the night of 19 August, the heaviest fighting yet occurred at Tabqa air base which involved medium and heavy weaponry as well as 15 government air raids around Tabqa. The ISIS had captured a string of nearby villages in the days before the attack, tightening its siege on the base. The assault started with a double suicide bombing near the entrance to the base, followed by a large-scale ground assault that consisted of 200 fighters, half of which were foreigners. The next morning, fighting subsided after the first assault wave failed to breach the base, but a second wave was launched in the afternoon. ISIS fighters encountered a mine field, heavy shelling and air strikes throughout the assaults. The mines were reportedly planted as part of an ambush set up by Syrian Army Special Forces based on previous observation of ISIS troop movements in the area. The fighting for the base continued until the morning of 22 August, as ISIS managed to capture the al-Tayyara checkpoint near the air base, but failed to break into the base itself. The base was reinforced with additional troops by plane over night while there were still clashes.

The SOHR reported that no more than 70 ISIS fighters were killed in the previous two days, since the attack on the base started, and denied other reported death tolls. According to the Beirut-based Al-Mayadeen TV, over 150 ISIS fighters were killed in the ambush near the base, while the Al Masdar news site reported more than 200 ISIS fighters being killed in the previous two days, including the ISIS field commander Umar Abdel-Rahman, a Tunisian. According to Al Masdar, 14 soldiers were killed and 29 others wounded between 18 and 22 August.

On the evening of 22 August, ISIS launched a third attempt to breach the base, after militant reinforcements arrived, starting with a suicide bombing against the airport gate. The attack was repelled, while air strikes also hit ISIS positions in the nearby city of Tabqa. According to Al-Masdar, a Syrian Army brigade later captured the M-42 highway leading to the city of Salamiyah in Hama Governorate and ended the ISIS siege on the Tabqa air base.

On 24 August, ISIS fighters breached Tabqa and took control over large parts of the air base. This attack occurred when the Army was already retreating from the base to the Ithriya area, leaving a small garrison behind. The base was eventually captured that day. According to Elijah J. Magnier, ISIS destroyed a MiG-21 fighter jet, while 15 other MiG-21's and all helicopters were evacuated from the base. The SOHR also confirmed all military aircraft was evacuated from the base during the retreat, while according to Charles Lister (Brookings Doha Center) ISIS captured a number of MiG-21B's, SA-16 MANPADS and AIM-9 Sidewinder missiles in the base, but noted that it was unclear whether the MiG-21B's were at all operational.

In the final assault, 170 soldiers were killed, while since the start of the battle 346 ISIS fighters and 195 soldiers had been killed. The number of dead soldiers was later updated to 200. Another 150 soldiers were reportedly captured, while 700 soldiers managed to retreat.

The next day, jet fighters launched seven air strikes on the surroundings of the air base. According to the SOHR, ISIS captured the al-Ajrawi farm nearby. It also reported that the ISIS prevented vehicles entering and leaving Ar-Raqqah province in fear of Syrian soldiers being transported out of the province. On 27 August, ISIS captured more than 20 soldiers in the farmlands of Tabqa, while 27 soldiers and 8 ISIS fighters were killed in fighting at the Athraya checkpoint in eastern Hama countryside. 60 soldiers who were hiding near the Athraya area managed to reach Salamiyah.

On 28 August, Syrian fighter jets launched a precise attack on an IS HQ in the city of Mohasan, during a meeting between military leaders and sharia judges. The attack resulted in the death of most leaders inside (numbering six), while others were wounded. Another airstrike occurred the same day against an IS camp near Baath Dam, killing and wounding dozens of insurgents. According to SOHR, ISIS executed 160 Syrian soldiers between 27 and 28 August.

Aftermath
An IS training camp in eastern Syria was bombed by the Air Force on 14 September, resulting in 17 IS casualties. A bridge in Deir ez-Zor used by the Islamic State was destroyed as part of the air campaign on the next day. Special forces and Syrian Army engineers blew up the Political Bridge, killing all the militants who were on it. IS thus lost the only available land route to move into parts of the city it controls. Supplies now have to be delivered by boats

At the beginning of October, 29 soldiers missing from the Brigade 93 base managed to reach the Army headquarters at Al-Hasakah city.