"These are the bodies that we have been able to collect so far," said a man wearing a black Islamic headband and an opposition flag around his neck.
The video appeared genuine and corresponded to other AP reporting on the events depicted.
Activists also reported clashes and shelling Thursday in the central province of Homs, Deir el-Zour in the east and Raqqa, Aleppo and Idlib provinces in the north. They said rebels shot down a helicopter carrying food and supplies to an army base near the northwestern town of Maaret al-Numan, killing the pilot and three other soldiers.
Also Thursday, Syria's Foreign Ministry complained to the United Nations and the U.N. Security Council about al-Qaida's activities in Syria, saying that Damascus has been fighting the group for two years.
The Syrian government denies there is an uprising and says it is fighting terrorists carrying out a foreign conspiracy.
The letter came a day after the leader of the most formidable rebel group in Syria pledged allegiance to al-Qaida but distanced himself from a claim that his Islamic extremist faction had merged with the terror network's Iraqi branch.
Al-Qaida in Iraq said Tuesday that it had joined forces with Jabhat al-Nusra or the Nusra Front — the most effective force among the disparate rebel factions fighting to topple Assad. It said they had formed a new alliance called the Islamic State in Iraq and the Levant.
In other developments, U.S.-based Human Rights Watch accused Syria of committing war crimes by indiscriminate and sometimes deliberate airstrikes against civilians, killing at least 4,300 people since the summer.
The regime's air power is its biggest advantage in the civil war, helping to repel rebel advances on Damascus and to prevent a rival government from setting up in the northern stronghold.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.