Troops backed by tanks encircled Rastan on Sunday morning and began firing heavy machineguns in the streets of the town of 80,000 people, 25 km north of the restive city of Homs, a resident of Rastan who witnessed the operation, told Reuters by telephone.
"Rastan's main clinic is full of wounded people and there is no way to get them to a hospital. Tanks are all around the town and they are firing heavily," said the witness, a lawyer who declined to be named for fear of reprisals.
"This is pure revenge," he said, referring to thousands of protesters who demanded on Friday the removal of Assad in one of the largest demonstrations in the region since the uprising against the government erupted in southern Syria on March 18 and spread across the country.
Rastan, a relatively prosperous town in an agricultural region, is on the main northern highway leading from Damascus to Syria's second city Aleppo.
The lawyer said internet, water, electricity, land lines and most mobile telephone links had been cut, a step commonly used by the military before they storm urban centres.
Protests in Syria have continued despite the increasing force used to crush demonstrations that began with demanding political freedom and an end to corruption, but are now calling for the removal of Assad.
The president has responded to the growing protests, the biggest challenge to his rule, by intensifying a military crackdown that has killed hundreds.
Rights groups estimate at least 1,000 civilians have been killed by security forces, the army and gunmen loyal to Assad in the past 10 weeks. They said 10,000 people have been arrested, with beatings and torture commonplace.
Authorities blame armed groups, Islamists and foreign agents for the violence and say at least 120 soldiers and police officers have been killed since the protests erupted in March. Activists say secret police killed scores of soldiers for refusing to fire at civilians.
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