Syrian security forces mutinied in the northern town of Jisrash Shugur on Monday.
The Syrian state claims that armed gangs attacked a checkpoint killing 120 people.
But eyewitnesses say that the state was quelling a mutiny by forces who refused to put down anti-regime protesters.
“I think they executed policemen who refused to open fire on demonstrators,” said one activist.
The government has launched a bloody crackdown on the pro-democracy movement.
President Bashar al-Assad has been in power since 2000 after succeeding his father.
Hundreds of people have been killed in the last two months.
Snipers have shot people attending funerals for dead protesters.
The regime has sent tanks into some towns including Homs, which has been at the centre of the revolt.
The state has previously claimed that armed gangs attacked government forces, in an attempt to justify its repression.
Syrian state TV has said that this most recent incident has led to people begging the army to swarm into the town.
Residents have denied this, saying the army has shot protesters there.