Activists say Syrian military forces have clashed with army defectors using machine guns and heavy weaponry in the country's east.
The British-based Syrian Observatory for Human Rights says 10 Syrian soldiers were killed in the clashes that took place late Friday in the town of Deir el-Zour.
The group said Saturday that there were also several casualties among the group of armed dissidents known as the Free Syrian Army.
The Local Coordination Committees activist network also reported fierce clashes, followed by house-to-house raids by troops searching for defectors.
Syria's 8-month uprising has grown increasingly militarized.
On Friday, the military blamed terrorists for an attack a day earlier in the central city of Homs, saying six pilots and four others were killed in an ambush.
Arab officials are preparing plans for sanctions against Syria over its failure to let Arab League monitors oversee an initiative aimed at ending the Syrian government's violent crackdown on protests.
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