Syrian opposition activists said a massacre by government troops was underway Friday night in the city of Homs, a centre of the unrest in the country for nearly a year, dpa reported.
Arabic broadcaster Al Jazeera cited opposition sources alleging that at least 100 people had died and 400 were injured. Mortars were reportedly being used to shell civilian targets.
A physician in a hospital said that blood supplies were short and donations were urgently needed.
"We are confronting a death machine," he said by telephone. "People are dying."