A suicide bomber has attacked the US embassy in the Turkish capital Ankara, killing a guard, officials say.
The blast, at a side entrance of the heavily guarded compound, sent debris flying into the street.
The US has warned its citizens not to visit diplomatic missions in Turkey until further notice.
No group has said it carried out the attack, but Interior Minister Muammer Guler said the bomber, who also died, was a far-left militant.
Mr Guler suggested that the bomber might have been a member of the outlawed Revolutionary People's Liberation Party-Front (DHKP-C).
He also said the attacker was believed to have been a Turkish national.
Turkey and the US have denounced the incident as terrorism.
White House spokesman Jay Carney said the US strongly condemned the "terrorist attack".
Ankara was last hit by a suicide bombing in September 2011, in an attack blamed on Kurdish militants.
A number of illegal groups ranging from Kurdish separatists to leftist and Islamist militants have launched attacks in Turkey in recent years.
'Like an earthquake'
US ambassador Francis Ricciardone briefed reporters outside the embassy shortly after the attack.
He said a guard at the embassy's side entrance had been killed in the blast at 13:15 (11:15 GMT), and a Turkish citizen had been wounded.
Turkish officials said the bomber had also died.
Later, the US state department confirmed a Turkish woman visiting the embassy had been seriously hurt.
Several staff members had been treated for minor injuries after being hit by debris.
Vatan newspaper's offices are opposite the blast scene, and their reporter Kıvanc El witnessed the incident.
"I was sitting in front of my computer. I heard a loud bang, and the whole building shook, as if it was an earthquake," he told the BBC's Turkish service.
"There was a cloud of smoke and I saw people scuttling away in panic. Ran downstairs in 30 seconds.
"There were two bodies lying on the floor, just inside the entrance with body parts scattered around. The fortified entrance had partially collapsed."
Banned Marxist group
Prime Minister Recep Tayyip Erdogan made a televised statement in which he called for a global effort to combat terrorism.
"This attack should remind us of the necessity of working together against terror. The roots of terror can only be cut by collaborating against terror together at an international level," he said.
The state department said it was working with Turkish police to make a full assessment of the damage.
The area around the embassy was swarming with police, said journalist Golnar Motevalli in Ankara.
Turkish broadcaster NTV named the suicide bomber as Ecevit Sanli, a DHKP-C member.
The channel said he had taken part in an attack on a club for military personnel in Istanbul in 1997, for which he was sent to jail.
The DHKP-C is designated a terrorist organisation in the US and Europe.
It has been blamed for a number of attacks since the 1970s, including some on US diplomatic missions.
Turkish police carried out a series of raids on suspected members in January.
The embassy building is heavily protected but the US has had long-standing plans to move its compound elsewhere for security reasons.
It was recently reported to be in the final stages of a deal to choose an alternative location.
The German and French embassies are situated close to the current building.