The leader of one of Syria's most powerful rebel groups, Jaysh al-Islam, has been killed in an air strike east of Damascus, according to the Syrian Army and opposition activists.
Zahroun Alloush and several other Jaysh al-Islam commanders were killed on December 25 when a warplane bombed a meeting place near the Syrian capital.
Alloush's death a month before expected peace talks between the Syrian regime and the opposition in Switzerland is a blow to rebels fighting to topple the government and a boost to regime forces who have been bolstered by the Russian military intervention in Syria since September.
The Saudi-backed Islamist group is one of the most powerful fighting against President Bashar al-Assad's regime. The group controls the Eastern Ghouta area on the eastern outskirts of Damascus.
The Syrian Observatory for Human Rights, a monitoring group, said on December 25 that the strike was mounted while Jaysh al-Islam leaders were discussing preparations for an attack on Syrian regime forces and allied fighters from the Lebanese Shi'ite Hizballah movement.
The monitoring group said it was unclear whether the warplane that killed the rebels was Syrian or operated by Russia, which has been conducting air strikes in the country for the past several months.
The Syrian Army, in a statement published on the state-run SANA news agency, said late on December 25 that Alloush was killed in a Syrian Army air strike.
It said that the strike was carried out after a series of aerial reconnaissance operations against "terrorist" groups and their headquarters in Eastern Ghouta.
Hizballah's Al-Manar TV led with the news of Alloush's killing, touting it as a victory.
However, Mazen al-Shami, an opposition activist based near Damascus, told The Associated Press that warplanes believed to be Russian fired 10 missiles at the site where Alloush and top commanders in his group were meeting.