NEW : U.S. is pleased Syria gave the opposition some `` breathing space '' to negotiate with Assad. Adviser : Protesters have `` legitimate grievances , '' but there are extremists . The Turkish government says 10,757 Syrians have fled across the border . `` We must change this tyrannical regime , '' a former political prisoner says .
NEW : U.S. is pleased Syria gave the opposition some `` breathing space '' More than 1,300 civilians have been killed in the unrest , an activist group says . Adviser : Protesters have `` legitimate grievances , '' but there are extremists . The Turkish government says 10,757 Syrians have fled across the border . `` We must change this tyrannical regime , '' a former political prisoner says .