ANKARA, Turkey - In the second deadly assault on a U.S. diplomatic post in five months, a suicide bomber struck the American Embassy in Ankara on Friday, killing a Turkish security guard in what the White House described as a terrorist attack.
Washington immediately warned Americans to stay away from all U.S. diplomatic facilities in Turkey and to be wary in large crowds.
Turkish officials said the bombing was linked to leftist domestic militants.
Emergency personnel are seen in front of a side entrance of the U.S. Embassy in the Turkish capital, Ankara, after a suspected suicide bomber detonated an explosive device, Friday. The bomb appeared to have exploded inside the security checkpoint at the entrance of the visa section of the embassy. A police official said at least two people are dead.
The attack drew condemnation from Turkey, the U.S., Britain and other nations and officials from both Turkey and the U.S. pledged to work together to fight terrorism.
"We strongly condemn what was a suicide attack against our embassy in Ankara, which took place at the embassy's outer security perimeter," said White House spokesman Jay Carney.
"A suicide bombing on the perimeter of an embassy is by definition an act of terror," he said. "It is a terrorist attack."
Turkish Prime Minister Recep Tayyip Erdogan said police believe the bomber was connected to a domestic leftist militant group. Carney, however, said the motive for the attack and who was behind it was not known.
A Turkish TV journalist was seriously wounded in the 1:15 p.m. blast in the Turkish capital, and two other guards had lighter wounds, officials said.
The state-run Anadolu Agency identified the bomber as Ecevit Sanli. It said the 40-year-old Turkish man was a member of the outlawed Revolutionary People's Liberation Party-Front, or DHKP-C, which has claimed responsibility for assassinations and bombings since the 1970s.
The group has been designated a terrorist organization by the United States but had been relatively quiet in recent years.
Hillary Rodham Clinton, in her farewell speech to State Department staff moments after she formally resigned as secretary of state, said "we were attacked and lost one of our foreign service nationals."
She said she spoke with U.S. Ambassador Francis Ricciardone, "our team there and my Turkish counterpart. I told them how much we valued their commitment and their sacrifice."
Sen. John Kerry, the incoming secretary of state, also was briefed.
The U.S. Embassy building in Ankara is heavily protected and located near several other embassies, including those of Germany and France.
U.S. diplomatic facilities in Turkey have been targeted previously by terrorists. In 2008, an attack blamed on al-Qaida-affiliated militants outside the U.S. Consulate in Istanbul left three assailants and three policemen dead.
On Sept. 11, 2012, terrorists attacked a U.S. mission in Benghazi, Libya, killing U.S. Ambassador Chris Stevens and three other Americans. The attackers in Libya were suspected to have ties to Islamist extremists, and one is in custody in Egypt.
Friday's bombing occurred at a security checkpoint at the side entrance to the U.S. Embassy, which is used by staff.
State Department spokeswoman Victoria Nuland said a man detonated a suicide vest at the checkpoint on the outer perimeter of the embassy compound.
"He came to this first point of access to the compound ... where you have to have your ID checked, you have to go through security," Nuland said.
The guard who was killed was standing outside the checkpoint, while the two wounded guards "were standing in a more protected area," said Interior Minister Muammer Guler said.
The two were treated on the scene and did not require hospital treatment, he said.
"The level of security protection at our facility in Ankara ensured that there were not significantly more deaths and injuries than there could have been," Nuland told reporters in Washington.
"This is one of the compounds where we have been making steady security upgrades over the last decade," Nuland said. "And in fact, the attack was at one of the exterior compound access sites. So it was far from the main building, and it was a result of the way that was hardened that we only lost the one local security guard. And in fact, there were other security guards inside the building behind the glass who were only shaken up by this."
While praising its security and the response of Turkish authorities, Nuland noted that the embassy in Ankara is due for a completely new compound in future. She described the current main building as a 1950s complex that "needs a full upgrade."
The Hurriyet newspaper said staff at the embassy took shelter in a "safe room" inside the compound soon after the explosion.
Police swarmed the area and immediately cordoned it off. Forensic investigators in white outfits and gloves soon combed the site.
TV news video showed the embassy door blown off its hinges. The blast also shattered the windows of nearby businesses, littering debris on the ground and across the road. The inside of the embassy did not appear to be damaged.
Television video also showed what appeared to be a U.S. guard in a helmet and body armor surveying the area fromthe roof of an embassy building.
In a statement, the U.S. Embassy thanked Turkey for "its solidarity and outrage over the incident."
Ricciardone declared that the U.S. and Turkey "will continue to fight terrorism together," and described the U.S. Embassy compound as secure.
"From today's event, it is clear that we both suffer from this terrible, terrible problem of today's world. We are determined after events like this even more to cooperate together until we defeat this problem together," he said.