BEIRUT — A suicide attacker detonated a bomb Friday outside the U.S. Embassy in Turkey, killing himself and a Turkish guard but failing to damage the main embassy building or cause serious casualties among U.S. personnel, authorities said.

Turkish officials later identified the suicide bomber as a member of an outlawed, far-left domestic group.

The White House labeled the incident in Ankara a terrorist attack, and U.S. officials praised Turkish authorities for their quick response.

“We have worked shoulder to shoulder with the Turks to counter terror threats,” White House spokesman Jay Carney told reporters in Washington.

Turkey is a staunch U.S. ally and the eastern bulwark of the NATO alliance.

“The attack aimed to disturb Turkey’s peace and prosperity and demonstrated a need for international cooperation against terrorism,” Turkish Prime Minister Recep Tayyip Erdogan said.

The bombing comes almost five months after a devastating Sept. 11 assault by suspected Islamist militants on a pair of U.S. diplomatic compounds in Benghazi, Libya, resulting in the deaths of U.S. Ambassador J. Christopher Stevens and three other American personnel.

That attack generated blistering criticism of lax security in Benghazi and prompted a review of security practices at U.S. diplomatic outposts worldwide.

On Friday, U.S. officials said that the procedures in place prevented further bloodshed and damage.

“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,” U.S. State Department spokeswoman Victoria Nuland told reporters in Washington.

Among the injured was Turkish television journalist Didem Tuncay, 38, a former reporter for the private NTV channel, who was reported in critical condition.

U.S. Ambassador Francis J. Ricciardone visited her in the hospital and told reporters that that the journalist had come to the embassy on Friday in response to his invitation to tea, the semiofficial Anadolu news agency reported.

 The ambassador lauded the slain guard, identified as Mustafa Akarsu, 36, as a “hero.” Two other guards suffered minor injuries.

The bomb dislodged masonry from a front wall and blasted an entry door off its hinges, photos from the site show. Flying debris injured several embassy staffers, who were treated at the scene.

The embassy is on a heavily secured street in the center of the Turkish capital, close to the German and French embassies.

U.S. embassies generally have a much higher degree of protection than small American missions like the ill-fated installations in Benghazi.

Buildings housing U.S. diplomats are typically set back from public thoroughfares; gaining access generally involves passing through several layers of security checkpoints and searches.

After the Ankara attack, U.S. authorities warned Americans in Turkey not to visit the embassy or U.S. consulates and to avoid demonstrations and large gatherings.

Media reports in Turkey identified the attacker as Ecevit Sanli, a member of the outlawed Revolutionary People’s Liberation Party/Front, which espouses an anti-U.S. and anti-capitalist agenda. The bomber’s motives remained unknown.

The far-left group _ considered a terrorist organization by Turkey and the United States _ has been implicated in attacks going back to the 1970s, authorities said, reportedly including several involving U.S. targets.

Sanli was imprisoned in 1997 for attacking a military guest house in Istanbul with a flame thrower, reported the website of Hurriyet Daily News, an English-language Turkish newspaper. He was released on probation in 2002, the newspaper reported.

Friday’s attack occurred at a moment of considerable tension in the region.

Turkey shares a more than 500-mile border with Syria, where a bloody, almost two-year rebellion is raging against President Bashar Assad. Turkey has called for Assad to step down and has lent considerable support to Syrian rebels. Some Turkish leftists have accused their government of bowing to U.S. pressure to help topple Assad.

The U.S., which has also called for Assad’s resignation, is among three NATO nations deploying Patriot missile batteries in Turkey in what the alliance calls a defensive move against a possible missile attack from Syria.

Syria and its allies have labeled the deployment a dangerous provocation.

In recent years, Turkey has seen attacks on its soil from left- and right-wing militants, as well as from Islamic extremists and Kurdish nationalists.

In 2008, gunmen reportedly linked to al-Qaida attacked the U.S. Consulate in Istanbul, resulting in a shootout that left three assailants and three police officers dead.

In November 2003, four truck bombs left 67 dead and hundreds wounded in strikes in Istanbul targeting a pair of synagogues, British-based HSBC bank and the British Consulate. Turkish authorities blamed Islamic militants linked to al-Qaida.

• Patrick J. McDonnell, Associated Press