A man injured in an explosion in central Damascus on Tuesday was carried from the scene.
BEIRUT, Lebanon — Deadly bombings hit the center of Damascus and a major Syria border crossing into Turkey on Tuesday as President Obama strongly suggested that he would not be rushed into military entanglements in the Syria conflict, where evidence of chemical weapons use has raised the possibility of an American intervention.
The blasts in Syria, which killed at least 13 people in the capital and at least five at the Bab al-Hawa crossing in northern Syria, came a day after an attempted assassination of Syria’s prime minister in central Damascus from a bomb aimed at his motorcade. The prime minister, Wael Nader al-Halqi, survived the attack but at least five others including a bodyguard were killed, Syria’s state news media reported.
In Washington, Mr. Obama told reporters at a wide-ranging news conference that despite an American intelligence assessment last week that there was evidence that chemical weapons had been used in Syria, the evidence had not yet surpassed his “red line” for a change of American strategy regarding the conflict, in which President Bashar al-Assad is fighting to stay in power against an increasingly violent insurgency.
“We don’t know how they were used, when they were used, who used them; we don’t have chain of custody that establishes what exactly happened,” Mr. Obama said. “And when I am making decisions about America’s national security and the potential for taking additional action in response to chemical weapon use, I’ve got to make sure I’ve got the facts.”
If investigations prove that the Syrian government had used chemical weapons in the conflict, Mr. Obama said, “we would have to rethink the range of options that are available to us.”
Mr. Obama’s remarks came against a backdrop of increasing pressure on the administration to be more precise about what would constitute the basis for an American intervention in Syria if chemical munitions were used, which he has called a “game changer.”
While some members of Congress have said the threshold for more active American involvement has been crossed, the administration has resisted. There also appears to be little American public appetite for a military engagement in Syria, according to a new New York Times/CBS News poll.
The United States is the largest donor of humanitarian assistance to civilians of the two-year-old Syrian conflict and has called on President Assad to resign in a negotiated political transition. The Obama administration has provided nonlethal aid to the insurgents but has resisted requests to provide them with weapons.
The violence in Syria on Tuesday at first centered around a booby-trapped car in Damascus that exploded near the back door of a building that used to house the Ministry of Interior, according to the Syrian Observatory for Human Rights, an organization, based in Britain, with a network of local antigovernment activists in Syria. State television said the dead were all civilians.
In footage on state television, fire trucks and ambulances could be heard in the background as a camera panned over a scene of debris, bloodstains on the ground and dented cars with broken windows. A thick spiraling cloud of back smoke engulfed the area as passers-by spoke on their cellphones and looked around in disbelief.
It was not clear if any individual was targeted, and no group immediately claimed responsibility. The government blamed its armed opponents, while the opposition Local Coordinating Committees blamed the government, as has often happened in a war in which information is a weapon and each side seeks to demonize the other.
Later at the Bab al-Hawa crossing into Turkey, Syrian activists and residents on the Turkish side said Syrian warplanes bombed refugee encampments on the Syrian side. The Syrian Observatory uploaded video on the Internet to corroborate the assertion, showing the aftermath of an explosion. In the Turkish town of Reyhanli, near the crossing, residents said they believed at least five people on the Syrian side were killed and a flock of sheep destroyed.
An array of disparate groups are seeking to topple Mr. Assad, including the blacklisted Al Nusra Front, which recently pledged allegiance to Al Qaeda and has claimed responsibility for bombings in the capital and other attacks that have killed civilians. Other rebel groups say they reject such tactics.
Hania Mourtada reported from Beirut, and Rick Gladstone from New York. Reporting was contributed by Anne Barnard from Beirut, Sebnem Arsu from Istanbul and and Neil MacFarquhar from the United Nations.
