BEIRUT (AP) — The current international peace plan seeking to stop Syria’s civil war suffered a major setback Wednesday when an al-Qaida-inspired militant group rejected a cease-fire proposed by the international envoy.

Lakhdar Brahimi, the U.N.-Arab League envoy for Syria, said the government in Damascus and some rebel leaders had agreed to a four-day truce during the Muslim Eid al-Adha holiday, which starts Friday.

The modest scope of the proposal reflected how short the international community is on ideas — and even that appeared doomed. Both sides have agreed to previous, more ambitious cease-fires in the past only to break them, and neither side shows much interest in stopping the fight now.

The Syrian government denied it has made a decision, saying it is studying the proposal, and rebel leaders have expressed doubts.

An extremist group, Jabhat al-Nusra, which has joined the fight against President Bashar Assad, also rejected the truce.

“There will be no truce between us and the prideful regime and shedder of the blood of Muslims,” the group said in a written statement posted Wednesday on militant websites. “We are not among those who allow the wily to trick us, nor are we ones who will accept to play these filthy games.”