Syrian security forces shot dead five people and wounded more than 100 others in Talbisa and Rastan on Sunday after tanks encircled the towns near the central city of Homs, an activist told Agence-France Presse.
The activist, who asked not to be named, said three people were killed in Talbisa and another two in nearby Rastan. More than 100 wounded were taken to hospitals in Homs, a flashpoint of anti-regime protests.
Another activist, contacted by telephone from Nicosia, said several people were wounded as security forces unleashed "intense gunfire" in Rastan and Talbisa, after tanks sealed off both towns.
"Dozens of tanks at dawn encircled the towns of Rastan and Talbisa, as well as the village of Deir Maaleh," the activist told AFP.
The three are all located between Homs, which is Syria’s third-largest city, and Hama, on a stretch of highway north of Damascus that was cut off by tanks during the operation.
Security forces were carrying out searches in Talbisa, where a large crowd took to the streets on Friday for an anti-regime demonstration, said Rami Abdul Rahman, head of the London-based Syrian Observatory for Human Rights.
Also on Sunday, Syrian doctor and activist Mohammed Awad al-Ammar was charged with "damaging the prestige of the state and spreading false information," Abdul Rahman told AFP by telephone.
The doctor, who works at a hospital near Daraa, a hotspot of the revolt, was arrested on April 29 shortly after meeting with a high-level military official to propose a "democratic solution" to Syria’s political crisis, he said.
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 kilometer (16 miles) 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.
The 45-year old leader has also lifted emergency law and promised reforms the opposition say have not changed the nature of Syria where the ruling Baath Party has banned all opposition and political freedoms since 1963.
"I was hearing the bullets and the protesters chanting ‘the people want the overthrow of the regime’ at the same time," the witness, a resident of the city, said by telephone.
Demonstrations have been held nightly in Deir al-Zor and other cities and towns to circumvent heavy security which has intensified in recent weeks after street demonstrations grew in numbers and tanks were deployed in and around urban centers.
Human rights campaigners said a night-time rally took place on Saturday in the town of Binish in the northwestern province of Idlib in protest against arrests on Friday, when the biggest demonstrations typically occur after weekly prayers.
The Syrian National Organization for Human Rights said security forces shot dead 12 demonstrators on Friday during protests in 91 locations across Syria.
"The authorities are still pursuing the calculated course of using excessive violence and live ammunition to confront mass demonstrations," the organization said in a statement.
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.
Syrian authorities say 143 soldiers, security forces and police have been killed.
Foreign journalists are barred from travelling inside Syria, making it difficult to report on the unrest and verify witness accounts.
The government initially responded to the revolt by offering some concessions, including lifting the state of emergency in place for nearly five decades, but coupled this with a fierce crackdown.
The opposition has dismissed calls for dialogue, saying that could only take place once the violence ends, political prisoners are freed and reforms adopted.