Elite Syrian troops in tanks supported by helicopter gunships swept through the country's restive north on Friday, killing rebellious anti-government protesters even as other Syrians escaped to Turkey.

After another day of protests in several locations against the government of President Bashar al-Assad, activists said Syrian security forces had killed at least 32 demonstrators. The activists said seven protesters were killed as they tried to tear down a giant poster of Mr. Assad in the seaside town of Latakia.

In Washington, the White House denounced what it said was Syria's “outrageous use of violence” in the government's three-month-old crackdown on pro-democracy protesters. The U.S. said Mr. Assad was leading Syria on a “dangerous path.”

More than 4,000 Syrians have fled across the border to Turkey, where encampments of tents have sprung up over the last several days. Turkish Prime Minister Recep Tayyip Erdogan, a long-time ally of Mr. Assad, accused his government of “savagery.”

At the United Nations, diplomats held new talks on a draft resolution condemning the violence, but failed to reach an agreement. Many Western nations support the measure, but Russia and China have voiced opposition.

U.N. Secretary-General Ban Ki-moon tried several times to call Mr. Assad, but U.N. officials said the Syrian leader has refused to take the calls. Later, Mr. Ban said the use of military force against civilians was “unacceptable,” and he expressed concern about the carnage.

Witnesses and activists say at least 10 deaths occurred in the northwestern province of Idlib. The military shelled targets in the provincial city of Maaret al-Numan. State-run news reports said an armed group had attacked security forces in the city and set several government buildings on fire.

Meanwhile, witnesses and activists say security forces used live ammunition to disperse anti-government protesters in several other cities. The witnesses say protesters were killed in Damascus and in the southern Daraa region.

A separate military siege unfolded in Jisr al-Shughour, a town in the northern region near the Turkish border. Military forces moved into the town after the government said “armed gangs” in the region earlier in the week killed 120 security personnel.

Rights groups say at least 1,100 people have been killed in the Syrian crackdown that began in March and more than 10,000 people arrested.