BEIRUT — Syrian forces overran a mountain enclave near the Mediterranean coast Wednesday, seizing the territory back from rebels as a serious escalation in violence signaled both sides are using more powerful weapons.

With the bloodshed ramping up, France joined the U.N. peacekeeping chief in declaring Syria was in a state of civil war.

“When many groups belonging to the same people tear each other apart and kill each other, if you can’t call it a civil war, then there are no words to describe it,” French Foreign Minister Laurent Fabius told a news conference in Paris.

The battle for Haffa, in the mountains of Latakia province, raged for eight days as regime forces shelled the village to drive out rebels. The operation apparently was part of a larger offensive to retake areas that had fallen into rebel hands.

State television said regime forces had “cleansed” Haffa of “armed terrorist groups” and the Foreign Ministry urged U.N. observers to immediately head there “to check what the terrorist groups have done.”

It wasn’t immediately clear whether the U.N. observers would be able to reach Haffa. On Tuesday, an angry crowd hurled rocks and sticks at the U.N. mission’s vehicles, forcing them to turn back. None of the observers was hurt.

Sausan Ghosheh, a spokeswoman for the observers, said they have been trying to reach Haffa since June 7.

Hundreds of rebel fighters believed to have been holed up in Haffa and nearby villages pulled out overnight, said Rami Abdul-Rahman, director of the British-based Syrian Observatory for Human Rights, citing a network of activists on the ground.

On another front, fireballs of orange flames exploded over the central city of Homs, where Syrian forces fired a continuous rain of shells that slammed into the rebel-held neighborhoods of Khaldiyeh, Jouret al-Shayyah and the old city.

Recovering Haffa was particularly significant to the regime because the town is about 20 miles (30 kilometers) from President Bashar Assad’s hometown. Latakia province is the heartland of the Alawite minority to which Assad and the ruling elite belong.

As the violence spiked, both sides in the conflict appeared to be using heavier weapons.

U.N. observers reported Syrian helicopters were firing on Haffa and other restive areas, and amateur videos posted online by activists suggest the opposition is using powerful anti-tank missiles.

“There are arms being delivered, and on both sides,” Fabius said.

Although the Syrian rebels are outgunned by the well-armed Syrian army, weapons have been flowing across the country’s borders from neighboring Turkey, Iraq and Lebanon. The rebels also say they buy weapons from Syrian soldiers looking to make a profit.

Tensions over the issue flared Wednesday between the U.S. and Russia as they traded blame for the violence in Syria.

U.S. Secretary of State Hillary Rodham Clinton held to her explosive accusation that the “latest information” in U.S. hands is that Russia is sending attack helicopters to Assad’s regime. Russian Foreign Minister Sergey Lavrov fired back by alleging the U.S. has sent military support to the region.

“We have repeatedly urged the Russian government to cut these military ties completely and to suspend all further support and deliveries,” Clinton told reporters in Washington. “We know, because they confirm, that they continue to deliver and we believe that the situation is spiraling toward civil war. It is now time for everyone in the international community, including Russia ... to speak to Assad in unified voice and insist that the violence stop.”

Lavrov rejected the charge, saying his government was completing earlier weapons contracts with Syria for air defense systems to be used exclusively for self defense against “an armed attack from the outside.”

“We are not supplying either to Syria or anywhere else things that are used in fighting with peaceful demonstrators, in contrast to the United States, which regularly supplies such special means to countries in the region,” Lavrov said during a trip to Iran.

Russia has emerged as Syria’s most important ally and protector, blocking strong action at the U.N. Security Council and speaking against any foreign military intervention.

Moscow’s pro-Syria stance is motivated in part by its strategic and defense ties to Damascus, including weapons sales.

British Foreign Secretary William Hague also said weapons were flowing to both sides and called on Russia to halt supplying arms to the Assad regime.

“We have seen signs — rather anecdotal signs — of an increased availability of arms to the opposition,” he said during a trip to Afghanistan. “And so this is a deteriorated situation where Russia has an important responsibility due to its relationship with Syria and its position on the Security Council.”

Russia’s stance is coming under deeper scrutiny now that the conflict is looking more like civil war every day. France’s statement that Syria was in a civil war echoed a similar statement by U.N. peacekeeping chief Herve Ladsous on Tuesday.

Syria’s Foreign Ministry expressed “astonishment” over the claims Wednesday.

“Syria is not witnessing a civil war but rather an armed conflict to uproot terrorism and confront killings, kidnappings, bombings ... and other brutal acts,” the ministry said.

Syrian authorities characterize rebels as terrorists and armed gangsters, and the uprising as a foreign plot to destabilize the country.

On Wednesday, a roadside explosion hit a convoy of aid workers in northwest Syria, causing three people to suffer minor injuries, the International Committee of the Red Cross said.

The two Syrian Arab Red Crescent volunteers and an ICRC staff member were traveling from Aleppo to Idlib when the blast hit their marked vehicles, the Geneva-based group said.

Red Cross spokesman Hicham Hassan said it was the first time a Red Cross staffer has been injured since the start of violence last year. Several members of the Syrian Arab Red Crescent have been killed, including the head of its branch in Idlib, who was shot dead in January.