At least five people were killed by Syrian security forces in the northern province of Idlib, activists and human rights advocates said on Monday.
Two army defectors were killed in clashes with government troops, activists said.
The Syrian Observatory for Human Rights said three civilians were killed in the province by security forces overnight.
Earlier Monday, the human rights observatory reported that clashes were taking place in Idlib between Syrian troops and army defectors.
Troops loyal to President Bashar Assad's regime armed with heavy machine guns targeted private homes during the clashes that began in the early morning, the London-based group said.
Idlib is known to be a hub for former army personnel attempting to flee the government crackdown on defectors by crossing into neighboring Turkey.
In the southern province of Daraa, a group of army deserters attacked a bus carrying government security forces on Monday, leaving several injured, according to the observatory.
Increasing clashes between defectors and regular army units might take Syria into a civil war, observers have warned.
Army deserters have formed the Free Syrian Army and have been launching attacks on government targets.
The United Nations estimates that in excess of 4,000 people have been killed in the government crackdown on protests calling for the ouster of Assad that started in March.
The government has blamed the uprising against Assad on armed gangs financed by Arab and Western countries.
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