Several Syrian rebel factions united on Thursday against the war-torn country's former al Qaeda affiliate, as clashes raged for a third day between anti-regime forces. Five rebel groups joined the powerful Ahrar al-Sham group to fight against the Fateh al-Sham Front, which changed its name from Al-Nusra Front last year after breaking ties with al Qaeda.
The clashes erupted earlier this week as rebels attended peace talks in the Kazakh capital Astana, building on a fragile nation-wide cease-fire.
Fateh al-Sham, which is excluded from the cease-fire and did not attend the Astana talks, has accused rebels of having brokered a deal to "fight Fateh al-Sham and isolate it". On Tuesday, the jihadist group attacked a base belonging to the Jaish al-Mujahideen faction, sparking fighting between it and rebel groups in the northern provinces of Idlib and neighbouring Aleppo.
"In the past hours a series of aggressions have targeted our blessed revolution, leading to total confrontation," Ahrar al-Sham said in a statement on Thursday.
This caused five rebel groups including Jaish al-Mujahideen and Suqur al-Sham to ask to become part of Ahrar al-Sham, it said.
"All attacks against members of the movement or its bases will be considered as a declaration of war," the statement warned.
The infighting comes after years of Fateh al-Sham battling alongside rebels against President Bashar al-Assad's forces in Idlib province, which is the last major bastion of the armed opposition. But Fateh al-Sham has been hit in recent weeks by a series of deadly air strikes, most believed to have been carried out by the US-led coalition fighting jihadists.
The Syrian Observatory for Human Rights, a Britain-based monitor, has said Fateh al-Sham appears to believe that local rebels were providing co-ordinates for the air strikes.
Both the Islamic State group and Fateh al-Sham are excluded from the nation-wide truce in force since December 30.
Syria's conflict has killed more than 310,000 people and displaced millions since it erupted in 2011 with the brutal repression of anti-government protests.
It has since evolved into a complex war, with the rise of jihadist groups and the involvement of international powers.