The 22-member Arab League has officially voted to extend the mandate of the observer mission to Syria by one month.

The mission would grow in size and will be trained by the United Nations, officials told the Associated Press on condition of anonymity, because they weren't authorized to speak with media. The observers' prior mandate ended officially last Thursday.

Even as the foreign ministers were meeting, intense clashes with army defectors forced government troops to withdraw from the center of one of the biggest Damascus suburbs, the second to fall in a week.

The United States government, meanwhile, is considering a bill proposed Sunday by New York Democratic Senators Charles Schumer and Kirsten Gillibrand, that would impose trade sanctions on Syria as long as President Bashar al-Assad continues his violent crackdown on dissidents.

The measure blocks financial aid and property transactions in the United States that involves Syrian leaders involved in the crackdown on anti-government protesters, and would require President Barack Obama to identify violators of human rights and call for reform and protection of pro-democracy demonstrators.

In addition, the bill prohibits the sale of high technology and telecommunications to Syria by any firm if the technology could be used for censorship or human rights abuses. Visas to the United States would also be denied under the bill.

The Syrian state-run SANA news agency said Sunday that an estimated 5,255 Syrian prisoners were released in the past week under a recent amnesty program, raising the total freed since November to more than 9,000 prisoners. There was no word on how many more are being held, however – and the Syrian Observatory for Human Rights estimated in a prior statement that the figure could be up to 100,000 or more, many of whom have been tortured, including women and children.

Some 6,000 protesters have been killed by government troops loyal to President Bashar al-Assad in the past 10 months, according to various estimates, including some groups affiliated with the United Nations.