Britain and France will put forward a United Nations Security Council resolution on Wednesday condemning Syria's crackdown on protesters, British Prime Minister David Cameron said.
"Today in New York, Britain and France will be tabling a resolution at the Security Council condemning the repression and demanding accountability and humanitarian access.
"And if anyone votes against that resolution or tries to veto it, that should be on their conscience," Cameron told parliament.
Britain, France, Germany and Portugal circulated a draft resolution condemning Syria at the UN Security Council last month, but diplomats say Britain has been working on a version with tougher language. Veto powers Russia and China have made clear they dislike the idea of council involvement.
United States State Department spokesman Mark Toner said that the U.S. would support a UN resolution against Syria.
"We believe that such a resolution will bring added pressure on Assad's regime and advance the international community's efforts to end the brutal repression on the Syrian people," Toner said.
Also on Wednesday, Turkey called on Syria to rein in violence against civilians and promised not to turn away refugees as some residents of a Syrian border town headed for the Turkish frontier in fear of a military assault.
"Syria should change its attitude towards civilians and should take its attitude to a more tolerant level as soon as possible," said Turkish Prime Minister Tayyip Erdogan, who has had warm relations with Syrian President Bashar Assad.
Assad's government has accused armed bands of killing scores of its security men in Jisr al-Shughour and has vowed to send in the army to carry out their "national duty to restore security".
Accounts of the violence that began in the hilly town of Jisr al-Shughour on Friday vary, with officials saying gunmen ambushed troops and residents reporting an army mutiny.
The bloodshed has triggered international alarm that Syria may be entering an even more violent phase after three months of popular unrest that has cost more than 1,000 lives.
At Jisr al-Shughour, home to tens of thousands of people, residents said they were taking cover and bracing for attacks. Some 120 men, women and children fled into Turkey overnight to seek refuge, the Anatolian news agency said.
Erdogan, who has distanced himself from Assad since the Syrian uprising began, said Turkey would not "close its doors" to refugees fleeing Syria.
Rami Abdulrahman of the Syrian Observatory for Human Rights said troops had deployed in villages around Jisr al-Shughour, including Ariha to the east and on the main Latakia highway to the southwest.
Residents said about 40 tanks and armored vehicles were about 7 km from Jisr al-Shughour, which was now mostly empty, save for youth protesters.
Ali Haj Abrahim said his son Bilal, who had volunteered to help the wounded at the weekend, was shot by security forces on Sunday on the outskirts of Jisr al-Shoughour.
"Two machinegun rounds tore through his chest and his left shoulder. He was 26 with a geography degree, married four months ago. His wife is pregnant," Haj Ibrahim said.
"We are not taking condolences. We consider his martyrdom a wedding for the defense of freedom," he told Reuters.
Abdulrahman said there were protests against Assad on Tuesday in suburbs of Damascus, including Harasta and Douma, and in Deir Al-Zor and Qamishli in the northeast. Pro-Assad rallies were also held in some of the capital's suburbs.
The government has expelled independent journalists, making it hard to determine clearly what is happening in the country.
Despite enthusiasm for pro-democracy movements that have unseated presidents in Tunisia and Egypt, few Western leaders -- let alone their autocratic Arab partners -- have shown a willingness to intervene in Syria, an Iranian ally whose volatile mix of ethnic and religious groups sits astride a web of regional conflicts.
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