Syria pressed on with a crackdown on anti-regime dissent yesterday, dispatching troop reinforcements to the province of Homs.
Security forces were also sent near Damascus, activists said.
"Military reinforcements were sent to Rastan, deploying around the building housing military security, and to Qusseir," they added.
The Syrian army strengthened its presence in Qusseir, a town on the border with Lebanon, on Saturday and previous days after many civilians tried to flee the area.
The deployments come a day after activists reported that security forces had killed 12 civilians in Qusseir, in the central province of Homs, and one more in Hama, further north.
The Syrian Observatory for Human Rights, which carried the toll, said that the 12 in Qusseir died during raids for people wanted by the authorities.
The office of the UN High Commissioner for Human Rights in Geneva has said that the death toll from the crackdown on dissent since it began on March 15 has risen to more than 2,700.
Activists have frequently reported defections in military ranks and yesterday the Observatory said authorities conducted raids and arrests in the province of Idlib, bordering Turkey, "after more than 40 soldiers from the Nayrab boot camp escaped".
The Britain-based group also reported the death of four people, including that of Hassan Eid, the head of the surgery department at the state-run hospital in Homs, who was shot outside his home. Syrian state television said he was killed by "armed terrorist gangs".
Meanwhile, activists called for a rally yesterday to pay tribute to Zeinab Al Hosni, 18, whose mutilated body was discovered last week two months after her arrest, according to Amnesty International.