Syria's al-Qaida offshoot said on Monday it had killed leaders of an insurgent group it says is linked with DAESH in a suicide bombing of its headquarters in the south of the country. Nusra Front and DAESH are the two most powerful rebel groups fighting government forces in Syria and have been fighting each other since 2013 largely because of a power struggle between their leaders. A Nusra Front Twitter posting on Sunday night said Abu Ali al Baridi, the leader of the Yarmouk Martyrs Brigades, had been killed alongside other top leaders in a "heroic" suicide bombing, but gave no further details. A source in the area said a suicide bomber had blown himself up in a building in the Yarmouk Martyrs' stronghold of Jamla, a town near the Syrian Golan Heights and close to the border with Israel and Jordan in southwestern Deraa province Nusra Front also called on DAESH fighters, who number about 2,000 and who have acquired a large arsenal of weapons including tanks seized from Syrian army garrisons in the border area, to surrender themselves, a source in the area said. Along with fighters from Ahrar al-Sham, Nusra Front have been fighting the Yarmouth Martyrs for months, trying to more of the border area that was formerly patrolled by U.N. troops. Baridi, known as "The Uncle", was purportedly shown in a video this year pledging allegiance to DAESH's leader Abu Bakr al Baghdadi. But the Yarmouk Martyrs Brigade have publicly denied any ideological or organizational links with DAESH, and say Nusra Front is trying to discredit them.