The top US military officer warned Sunday that intervention in Syria would be "very difficult" and said it would be "premature" to arm the besieged country's opposition movement.

General Martin Dempsey, chairman of the US Joint Chiefs of Staff, told CNN that Syria was the focus of competing Middle Eastern states, notably Iran and Saudi Arabia, and posed different problems for the United States than Libya did.

"It's premature to take a decision to arm the opposition movement in Syria because I would challenge anyone to identify for me the opposition movement in Syria at this point," Dempsey said in an interview.

"There's indications that Al-Qaeda is involved and that they're interested in supporting the opposition. I mean there's a number of players, all of whom are trying to reinforce their particular side of this issue.

"And until we're a lot clearer about, you know, who they are and what they are, I think it would be premature to talk about arming them."

Dempsey identified "a Sunni-Shiite competition for, you know, regional control," of Syria being played out between Saudi Arabia and Iran as a key barrier to US intervention, as well as Damascus's "very capable," military.

"They have a very sophisticated, integrated air defense system. They have chemical and biological weapons. They haven't demonstrated any interest or any intent to use those, but it is a very different military problem," Dempsey said, noting he had not yet been asked to provide US military options on Syria.

"Intervening in Syria would be very difficult... And I think that the current path of trying to gain some kind of international consensus is the proper path, rather than to take a decision to do anything unilaterally."

"But, you know, I wear the uniform I wear to provide options when asked. And we'll be prepared to do that. But this would not be -- it was a big mistake to think of this as another Libya," he added.

Syrian President Bashar al-Assad, who for 11 months has defied pro-democracy protesters with a forceful military crackdown that has killed thousands of civilians, belongs to the ruling Alawite sect, an offshoot of Shiite Islam.

Alawites, who represent only 12 percent of Syria's mostly Sunni Muslim population, are closely tied to Iran.

Libya celebrated on Friday the first anniversary of the launch of its revolution that ousted Moamer Kadhafi. The conflict was won only with significant US and Western assistance, including months of aerial bombardments that weakened Kadhafi's grip on the country.

Syria forces fire on funeral, China urges bloodshed end
Damascus (AFP) Feb 18, 2012 - Security forces shot dead a mourner at a huge funeral on Saturday for demonstrators killed in rare protests in the Syrian capital, as a senior Chinese envoy issued a plea for the bloodshed to end.

The Damascus funerals were for four people, two of them teenagers, killed when security forces fired on protesters in the capital's Mazzeh district, which is overlooked by the presidential palace and houses many government offices and embassies, a human rights group and activists said.

"The funerals in Mazzeh turned into protests -- it was the closest major gathering to Omayyad Square" in the city centre, the head of the Syrian Observatory for Human Rights, Rami Abdul Rahman, told AFP.

Mohammed Shami, a spokesman for activists in Damascus province, echoed him.

"It's the first time there have been demonstrations of such a scale so close to the centre of Damascus," Shami said, adding that some 15,000 people had turned out despite snowfall.

He said the shootings, in which many people were wounded, were followed by a "wave of searches and arrests" across the leafy, upscale residential district.

"People hid wherever they could," he said. "State television didn't cover what happened even though it was only a short distance from the Radio and Television Organisation."

Activists described Friday's demonstrations in Damascus as "unprecedented", saying there were 49 in all, and called for a "day of defiance" in the capital on Sunday to galvanise support.

"We said from the onset that the day when huge demonstrations will spill out in Damascus and (Syria's second city) Aleppo, it will be the end of the regime," said Agnes Levallois, a Paris-based Middle East expert.

The continuing onslaught on the rebel city of Homs "has spurred many Syrians, who were still hesitating, to join the protest movement", said Levallois. "The wall of fear has really crumbled."

The Syrian Observatory said the security forces killed a total of at least 11 civilians across the country on Saturday.

In a message to Damascus residents on their "Syrian Revolution 2011" Facebook page, activists said: "The blood of the martyrs exhorts you to disobedience."

Security forces also kept up their pounding of the flashpoint central city of Homs as the Chinese envoy visited.

Rockets crashed into strongholds of resistance at the rate of four a minute on Friday, according to one activist. He warned that the city, Syria's third largest, faced a humanitarian crisis.

Thirteen of the 30 people killed on Friday were in the Homs district of Baba Amr, the Observatory said.

After morning talks with President Bashar al-Assad, Chinese Vice Foreign Minister Zhai Jun called on all sides to stop the violence and for planned elections, which have been denounced by the opposition, to go ahead peacefully, state media said.

Zhai, whose government has twice joined Russia in blocking UN Security Council condemnation of the Damascus regime's crackdown, said it was vital that "calm be restored as quickly as possible," state television reported.

"The position of China is to call on the government, the opposition and the rebels to halt acts of violence immediately," Zhai said, on the second day of talks with Syrian officials.

"We hope that the referendum on a new constitution as well as the forthcoming parliamentary elections pass off calmly," he added.

"China supports the reforms under way in Syria and the significant measures taken by the country in this field."

Assad said the unrest in Syria was "aimed at dividing the country and delivering a blow to its geopolitical position and historical role in the region," the official SANA news agency reported.

The office of Iraqi Prime Minister Nuri al-Maliki office said in a statement Baghdad was taking measures to secure its border with Syria against weapons smuggling and the unauthorised movement of people.

On Thursday, Syrian opposition groups rejected a newly drafted constitution that could end nearly five decades of single-party rule, and urged voters to boycott a February 26 referendum on the charter.

Deputy Interior Minister Hassan Jilali said that more than 14 million Syrians will be eligible to vote in the referendum, SANA reported, adding that 13,835 polling stations have been set up across the country.

Meanwhile, Hollywood star and UNHCR goodwill ambassador Angelina Jolie appealed for "intervention" in Syria, telling Al-Jazeera Balkans television: "It's so sad, so upsetting, it's so horrible what's happening."

And in the United States, NBC television reported that US drones were overflying Syria to monitor the violence, which activists say has left more than 6,000 people dead since last March.