BEIRUT, Lebanon — Syria announced on Wednesday that the village of Al Heffa in its Mediterranean hinterland, which United Nations monitors had been physically blocked from visiting to check on fears of a massacre there, had been “cleansed” of armed terrorist gangs, the government’s blanket term for the opposition.

Activists in the opposition said a ferocious blizzard of artillery shelling by the Syrian military had forced all residents of Al Heffa to flee.

The Syrian Foreign Ministry issued a statement declaring that the United Nations monitors, who are unarmed, were now invited to visit Al Heffa to inspect the situation after “security and calm” had been restored. It said that the armed groups had carried out “killing and terrorizing against the innocent citizens, and acts of looting and vandalism against public and private properties and shops.”

The ministry declaration represented a U-turn from a day before, when the United Nations monitors retreated after an angry mob had attacked their vehicles with stones and iron rods before they reached Al Heffa. Residents of the surrounding villages are mostly Alawites, the same minority sect of President Bashar al-Assad, while Sunni Muslims were the majority in Al Heffa.

A video posted on YouTube on Wednesday showed the mob attacking the vehicles, including a young man treating one vehicle like a trampoline.

The official version of that event was also different, claiming three residents were injured after being run over while trying to get the inspectors to stop to listen to their stories about how armed gangs had terrorized them, according to the government-run Syrian Arab News Agency.

Government opponents said Al Heffa was virtually empty, with hundreds of residents and opposition fighters moving over the roughly five miles of mountainous terrain toward the Turkish border or elsewhere inside Syria.

“We didn’t have enough medication to treat the injured, the roads were bad, and we were in danger,” said Ahmad, an opposition activist reached by telephone, who was helping people negotiate the rough terrain. He asked to be identified only by his first name because he often crossed the border.

Ahmad and another opposition member said 1,500 people had fled elsewhere in Syria or into Turkey, including 150 wounded who had crossed the border, with about 8 of them dying along the way. In Turkey, the semiofficial Anatolian news agency said 280 Syrians, including 20 injured, had come through in one crossing. It was impossible to resolve the difference in the counts.

“Al Heffa is now empty; we evacuated everyone,” said Ahmad. “There are only shabiha and security men there,” he said, referring to the pro-government militiamen often deployed alongside Syria’s armed forces. “All the homes have been shelled, and most of them are now destroyed.”

Fighters were killed on both sides, according to the two accounts, but it was impossible to ascertain the correct toll.

Amin, a resident of Al Heffa now recuperating in a hospital in Antakya, Turkey, said he had been at a demonstration there on Friday when helicopters attacked with what he described as rockets. Everyone fled into the surrounding fields, but shrapnel from the helicopter attack wounded him in his hands and arms to the extent that he could not hold a telephone, he said, using a speakerphone to talk from a government hospital.

“It was hard getting here,” he said, with helicopters shelling the convoy twice.

In the city of Homs, also the target of sustained government shelling, opposition fighters said there were at least 100 people injured, 15 critically, in a rudimentary field hospital. They could not be evacuated because government forces ringed the Old Homs neighborhood, said the head of the local coordination committee, who identified himself as Abu Bilal al-Homsi.

Even as the idea of a cease-fire under United Nations auspices became more remote by the day, outside powers were still seeking ways to bring it about. Laurent Fabius, the French foreign minister, echoed the head of United Nations peacekeeping operations, Hervé Ladsous, in saying that Syria could be considered to have entered into a civil war.

France, he said, would pursue making the six-point plan negotiated by the special envoy Kofi Annan enforceable under Chapter 7 rules of the United Nations, which allow for the use of force.

Russia and China have blocked two Security Council resolutions already, making clear that they will veto anything that might lead to the kind of foreign intervention used in Libya. The chances of agreement in the Council seemed to become even more remote as the United States and Russia traded accusations on Wednesday over arming Syria.

But in Damascus, the Foreign Ministry rejected the very idea of civil war, describing the conflict as a “war against the armed groups which chose terrorism as their way to achieve their objectives and conspire against the present and future of the Syrian people,” according to a statement carried by the government news agency.

The opposition also rejected the civil war label, saying it was a peaceful opposition movement demanding democratic change that took up arms in self-defense.

Hwaida Saad and Dalal Mawad contributed reporting. (Copyright 2012 The New York Times Company 06/14/12)