On 23 December 2016, alleging that rebels were
polluting the water spring in Ain al-Fijah with
diesel fuel, government forces conducted airstrikes and shelling on Wadi Barada. The
U.N.'s
Independent International Commission of Inquiry on Syria found no evidence of deliberate contamination of the water supply or demolition by the rebels, as the Syrian government maintained at the time, and no reports water contamination prior to the government's two air strikes on 23 December, and said these strikes cut off water from Damascus. The
open source investigative website
Bellingcat identified a video showing bombs impacting the building housing the spring. On 26 December, following airstrikes, the Syrian Army advanced into the valley from its outskirts and cliffs. 10 villages in the area were still held by the rebels. On 1 January 2017, pro-government website
Al-Masdar reported that the Syrian Army entered Ayn al-Fijah after civilians were evacuated by the
Syrian Arab Red Crescent. Heavy clashes in the town continued on the next day, as local
Jabhat Fateh al-Sham defenders attempted to halt the army and
Hezbollah's advance, according to the UK-based
Syrian Observatory for Human Rights (SOHR). Pro-government media reported that the government called for the rebels to surrender the water spring and restore the water supply for Damascus, and government forces proceeded to launch another attack on the following day, targeting the rebel-held village of
Basimah, capturing several sites around the village, including Basimah Orphanage, which they claimed was used as rebel base, Later that day, pro-government media claimed that a ceasefire deal had been reached. By 8 January, the government forces resumed their offensive, with al-Masdar saying they captured the hills northwest of
Deir Maqran, most importantly Tal Dahr Al-Masabi. On 10 January, al-Masdar said that
Russian Air Force conducted airstrikes against rebels in the area for the first time, while the Syrian Army also bombarded targets near the villages of Basimah and Deir Maqran. Multiple eyewitnesses told
Human Rights Watch that the bombardment of Basimah included the use of
chemical weapons: "they smelled
chlorine and described clinical signs and symptoms consistent with exposure to chlorine gas". The attacks took place in a civilian neighbourhood with no opposition armed presence and resulted in 46 civilians being treated in hospital for chemical weapons exposure. By then, about 50,000 residents of the valley had been displaced due to the fighting. and that they advanced into Ain al-Khadra. According to opposition sources, rebel forces managed to retake Ain al-Khadra soon after. Later that day, government media asserted that Ain al-Fijah,
Kafr al-Awamid,
Souq Wadi Barada,
Dayr Qanoo,
Dayr Miqrin and
Kafr az Zaytsigned a reconciliation agreement with the government, allowing technicians to fix the water springs and to raise the government flag over the towns. Several rebel units continued fighting, with government media reporting they attacked the technical crews with rockets. On late 14 January, government media said that maintenance vehicles arrived at the Ain Al-Fijah springs, along with some buses to transport rebels to Idlib Governorate. Later that day, however, government media reported that a sniper killed the Syrian Army general and chief negotiator Ahmad Ghadban as he was returning to the government lines. government forces declared they would resume the offensive. On the next day, Hezbollah-led forces advanced into the outskirts of Ain Al-Fijah and captured the hill of Ra’s al-Sirah to the town's north, resulting in fierce fighting with rebel fighters. On the other side, government media reported that the Syrian Army took control of most of
Al-Husseiniyah after the local elders agreed to a ceasefire deal with the government. Nevertheless, some parts of the town remained outside government control as some rebels reportedly refused to surrender or leave. patrol near the frontlines in Wadi Barada during late January 2016. Over the next days Hezbollah and army units slowly advanced into Ain Al-Fijah. On 19 January, government forces captured the village of
Afrah. Later that day, representatives of the local rebels and the government agreed to another ceasefire and to attempt to enforce the peace deal that the involved parties had agreed upon before Ahmad Ghadban's death, though this agreement, too, quickly collapsed, with both sides resuming hostilities. The rebels consequently blamed Hezbollah for the failure of the peace process, saying that the government could not restrain the Lebanese fighters. On 26 January,
al-Masdar News reported that another agreement had been reached between the government and the opposition fighters, with 2,600 rebels reportedly surrendering, leaving about 500 militants continuing to resist the pro-government takeover of Wadi Barada. On 28 January, however, SOHR and al-Masdar reported that the rebels finally retreated from Ain Al-Fijah as "goodwill gesture" for the implementation of the peace agreement of 26 January. The army subsequently took control of the town, and said the remaining opposition forces in the valley would be allowed to leave for
Idlib Governorate. A day later, the Army took full control of Wadi Barada, and the water supply to Greater Damascus was restored. Later on, the first buses carrying rebels left for Idlib, while al-Masdar News reported that some Jabhat Fatah al-Sham fighters attacked other opposition groups in Kafr az Zayt due to disagreements over the ceasefire. ==Talks for ceasefire and evacuation==