Defense Secretary Leon Panetta, speaking earlier, said Syria was lurching into dangerous territory and emphasized that Assad's government would be held responsible if it failed to safeguard its chemical weapons sites - a major concern for U.S. and regional security planners.
"This is a situation that is rapidly spinning out of control," Panetta told a Pentagon news conference.
One European national security official, reflecting the intelligence estimate of Washington and its allies, said that while the deadly bomb blast that wiped out key Syrian security officials was a huge setback for Assad, it was not necessarily a death blow.
U.S. officials said they were still assessing reports of the Damascus attack - but did not condemn it outright.
"The United States does not welcome further bloodshed in Syria. We note, however, that these men were key architects of the Assad regime's assault on the Syrian people," State Department spokesman Patrick Ventrell said.
U.S. officials said they did not have any information on Assad's whereabouts, and declined to speculate on who might have been behind the attack.
"I have seen nothing yet that would lead me to believe we have a clear determination of who was behind it. It certainly has all the elements of an al Qaeda-type attack, knowing that al Qaeda has a significant presence there," Rep. Mike Rogers, the Republican chairman of the U.S. House of Representatives intelligence committee, told Reuters.
"When there is confusion in the capital city all of these groups are going to try to take advantage of it."
Check out this article on the problem of chemical weapons falling into the hands of Al Qaeda--http://ca.news.yahoo.com/syria-brink-civil-war-jordanian-king-213636899.html
Check out this article on the problem of chemical weapons falling into the hands of Al Qaeda--http://ca.news.yahoo.com/syria-brink-civil-war-jordanian-king-213636899.html