Two northern Syrian villages near the Mediterranean port of Baniyas came under fierce attack by government forces Tuesday, according to witnesses and activists, as President Bashar al-Assad’s government intensified efforts to suppress an apparently strengthening protest movement.

An unknown number of protesters were killed and many more injured, according to people reached by telephone in Syria. The state-run Syrian Arab News Agency also reported that seven of the nine soldiers killed in street battles near Baniyas on Sunday were buried Tuesday.

Meanwhile, the New York-based Human Rights Watch issued a report accusing Syria’s security forces of flouting international law by firing at medical personnel or otherwise preventing them from tending to injured people Friday during some of the most intense clashes of the month-long unrest.

The White House again joined a growing chorus of international criticism of the Damascus government, issuing a statement that called the escalating use of force “outrageous” and condemned the security forces for allegedly blocking medical aid for the wounded.

On Tuesday, Syrian troops, security forces and armed pro-government thugs sealed off the villages of Baida and Ejnad about mid-morning and went house to house rounding up people, said Haitham al-Maleh, 80, a lawyer and human rights activist in Damascus.

Several hundred people, most of them young, were detained in Baida alone, according to a person affiliated with a local university who spoke on the condition of anonymity for fear of reprisal. Food deliveries were halted, and electrical and cellphone service was cut, the person added.

Some detainees were bound, beaten and forced to say, “With blood and soul, we save you, Bashar!” the university activist said.

When other villagers marched into the street to protest the crackdown, military and security forces opened fire on them, said Maleh, the lawyer.

Malath Aumran, 26, an activist who communicated with Baida residents over the Internet despite intermittent service, said that ambulances were blocked from retrieving the wounded and sometimes targeted by gunfire and that some injured people avoided local hospitals for fear of being arrested by security forces.

In a sign that some members of the security apparatus are sympathetic to the anti-government demonstrators, Aumran also cited reports that some soldiers had disobeyed orders to fire at protesters and that they themselves were killed.

But it has been impossible to verify his account and others because Syria has expelled most media organizations from the country and communication services are frequently down.

Through interviews with 20 Syrians, Human Rights Watch said it had documented that government forces targeted ambulances and doctors during bloody clashes Friday in Douma, Daraa and Harasta. The group also said that it had documented the deaths of 28 people that day.

The group, which said it has compiled lists of the dead and confirmed them by interviewing victims’ relatives, said the uprising has cost at least 170 lives. Other groups estimate that the death toll has reached 200.

Mansour is a special correspondent.