U.S. Secretary of State Hillary Clinton said Tuesday the U.S. is concerned about reports Russia is sending attack helicopters to Syria.
She also said Russia's claims that its arms shipments to Syria are unrelated to the conflict are "patently untrue." She said the U.S. has confronted Russia about stopping its continued arms transfers to the country.
Her comments come as Syrian rights groups say at least 34 people were killed Tuesday as government forces continued attacks on rebel strongholds, and U.N. monitors reported an angry mob prevented them from reaching the embattled western town of al-Haffeh.
The Local Coordination Committees, an activist group with members throughout Syria, said the casualties include 14 civilians dead in Deir al-Zour, 10 in Homs and eight in Aleppo. A number of government soldiers were among those killed.
Video footage from Syria
Also Tuesday, news agencies quoted United Nations peacekeeping chief Herve Ladsous as saying he believes Syria is now in a full-scale civil war, with a "massive increase in the level of violence."
But U.N. spokesman Martin Nesirky backed away from that characterization, telling reporters later "it is not for the U.N. to designate in that way." Nesirky, however, did confirm "a qualitative shift and intensification" of the violence in Syria.
Escalation in Al-Haffeh
The U.N. mission in Syria said a crowd of what appeared to be local residents in al-Haffeh surrounded U.N. observers and threw rocks and metal bars at their vehicles, firing gunshots at them as they left the area. None of the observers was injured.
The United States has indicated it fears Syrian forces are planning to massacre civilians in the town.
LCC spokeswoman Rafif Jouejati said rebel fighters in al-Haffeh have been attempting to smuggle trapped civilians over the nearby Turkish border.
"We know there were some 30,000 residents trapped in the town of al-Haffeh and we also know members of the Free Syrian Army were trying to help residents flee the area and get transported to Turkey and that a small number of residents have been safely transported, but there are still thousands of residents trapped," she said.
Clashes began last week when security forces initiated their attempt to capture the strategic Sunni Muslim town, located close to the port city of Latakia and the Turkish border - and used by rebels as an active smuggling route for people and supplies.
Hundreds of rebels are facing a continued tank and helicopter-backed assault in al-Haffeh. The helicopter attacks - confirmed by the U.N. on Monday - are regarded as a significant escalation by government forces.
Jouejati said that helicopter shelling and other aerial attacks by government forces have been occurring for months across Syria.
A spokesman for international envoy Kofi Annan, Ahmad Fawzi, said Tuesday that an international "contact group" will meet soon to discuss how to pressure Syria's government and opposition groups to implement the U.N.-Arab League envoy's tattered peace plan.
"What is lacking is implementation and that is why we count on these member states with influence on the parties during this meeting and as a result of this meeting to put irrevocable pressure on the parties to implement the plan and stop the killing and begin a political transition," he said.
No venue, date or list of participants for the meeting has been set.
Despite Secretary Clinton's outspoken comments on Russia Tuesday, Jeff Mankoff, an adjunct fellow for CSIS's Russia and Eurasia Program, said the U.S. still considers Russia as "the key" to any negotiated settlement in Syria.
"Russia is the only outside power that really has the leverage to the Assad government to lean on them and precipitate some kind of negotiated transfer of power--something along the lines of what you had in Yemen," Mankoff said.
The contact group meeting has been in doubt because of Western opposition to Syrian ally Iran's involvement. The Iranian foreign ministry Tuesday welcomed a Russian proposal for Iran to be included despite strong reservations from the United States, France and Britain.
British Foreign Secretary William Hague said he continues to hope for a peaceful solution.
"I don't think we can rule out options but the only option we are advocating and trying to bring about at this moment is the implementation of the Annan plan and a peaceful transition in Syria," he said.
But former U.N. official Mark Malloch-Brown, who worked closely with Mr. Annan at the U.N., echoed sentiments that Syria is on the verge of, if not already in, a state of civil war.
“The difference between civil war or near civil war is at times like this so slight, that the distinction almost loses meaning," he said. "But the fact is, hits by the [pro-government] Alawite militias on innocent civilians in Sunni villages, have now prompted tit-for-tat hits against Alawite civilians in other parts of the country. So you have got the whole escalating process of sectarian on sectarian violence which is really the essence of a civil war.”
On Monday, the United Nations accused Syrian security forces and pro-government "shabiha" militias of committing serious rights violations against children, including using them as human shields.
The report also said children have been "victims of killing and maiming, arbitrary arrest, detention, torture and ill-treatment, including sexual violence."
The U.S.-based group Human Rights Watch said the U.N. Security Council should impose an arms embargo and other targeted sanctions on the Syrian leadership in response to the abuses described in the report. It said Syrian children are paying a "horrendous price" in the conflict.
Analyst Hilal Khashan at the American University of Beirut said it appears the Syrian government is losing control of large parts of the country.
"The insurgency has spread throughout the country and the regime is now frantic," he said. "They are doing all they can do in order to redress the situation and the only way they know how to react is brutally and they don't mind bringing the country to civil war."
Syrian state TV said on Tuesday that government forces near the port city of Latakia were "chasing bands of terrorists" who were "destroying government buildings and terrorizing local residents." The report also said that "armed terrorists" stopped two buses carrying civilians near the Lebanese border.
VOA's Carla Babb and Andre De Nesnera contributed to this report from Washington and Lisa Schlein from Geneva.