The US has thanked Syria for foiling an attack on its embassy in Damascus.
Syria said three attackers were killed and a fourth captured as they tried to drive two cars at the compound. One security officer was killed.
Syrian media blamed Islamic extremists but no-one has said they carried out the attack. One car went up in flames but the second bomb failed.
The US, which lists Syria as a sponsor of terrorism, said it was grateful that the embassy staff's safety was ensured.
There were no reports of US casualties. There is currently no US ambassador to Damascus and very limited contact between the governments.
Damascus has seen sporadic unrest in recent years, including a reported attempt to bomb the Canadian embassy.
Security forces sealed off the Rawda area, which also houses other embassies and security installations.
"Three terrorists were killed and one was wounded," said Interior Minister Gen Bassam Abdel Majid.
It was, in his words, a "terrorist operation targeting the US embassy" and involving home-made bombs and automatic weapons.
Ayman Abdel-Nour, a Syrian political commentator who was in the area, said the attackers had run "toward the compound shouting religious slogans while firing their automatic rifles".
Grenades were reportedly thrown at the embassy's wall, said to be about 2.5m (8ft) high.
Witnesses said that after an initial exchange of fire, two of the attackers sought refuge in a nearby building but were pursued and gunned down by security forces.
US Secretary of State Condoleezza Rice thanked Syria's security forces and expressed condolences over the death of the guard.
"I do think that the Syrians reacted to this attack in a way that helped to secure our people and we very much appreciate that," she said.
Rice said Syria had helped to "secure our people"
"I think it's very early to try and speculate why this may have happened," she said.
White House spokesman Tony Snow said the US was "grateful for the assistance the Syrians provided in going after the attackers".
"We are hoping they will become an ally and make the choice of fighting against terrorists," he said.
The attack comes at a time of heightened tensions between Washington and Damascus, with bitterness in Syria over US support for Israeli military action in Lebanon.
The US accuses Syria of supporting the insurgency in Iraq and not doing enough to prevent weapons going to Hezbollah militants in Lebanon.
BBC Arab affairs analyst Magdi Abdelhadi says it is difficult to see what Islamic militants could gain by undermining stability in Syria.
But, our correspondent says, it is also probable that some elements have been angered by Syria providing intelligence to Washington on al-Qaeda.
On the fifth anniversary of the 11 September attacks, al-Qaeda deputy leader Ayman al-Zawahiri had warned there would be more attacks in Israel and the Gulf.