ALGIERS, Algeria Two convicted terrorists who had been freed in an amnesty carried out the suicide bombings at U.N. and government buildings that killed 37 people, an Algerian security official said Thursday.
One of the bombers was a 64-year-old man in the advanced stages of cancer, while the other was a 32-year-old from a poor suburb that has produced many Islamic militants, the security official said on condition of anonymity because he was not authorized to speak to the media.
The government has offered amnesties to try to end a 15-year Islamic insurgency, resulting in thousands of militants turning themselves in but sparking fierce criticism from the families of victims.
Al-Qaida's self-styled North African branch has claimed responsibility for the twin truck bombings Tuesday, which came 10 minutes apart. Victims included U.N. staff from around the world, police officers and law students.
President Bush called Algerian President Abdelaziz Bouteflika on Thursday to discuss the attacks and offer his condolences, White House press secretary Dana Perino said.
"President Bush reiterated his commitment to continuing U.S. counterterrorism cooperation in North Africa in order to bring the perpetrators to justice," she said.
The Interior Ministry raised the death toll in the bombings to 37, saying six more bodies had been found in the rubble of the U.N. offices.
In a posting on a militant Web site, Al-Qaida in Islamic North Africa described the U.N. offices as "the headquarters of the international infidels' den." It also posted photos of two men it said were the bombers. Both posed with weapons and wore camouflage, with the younger man smiling.
The Algerian security official identified the older bomber, who struck the U.N. offices, as Chebli Brahim, who was suffering from cancer and had two sons killed in army crackdowns on militants.
Brahim was a member of the Muslim fundamentalist party Islamic Salvation Front, or FIS. He was arrested in a sweep of FIS members after the government banned the party, the official said.
The younger bomber, who targeted Algeria's Constitutional Council building, was identified as Charef Larbi, from the impoverished Algiers suburb of Oued Ouchayeh, the official said. He had been arrested on the charge of "supporting terrorist groups" and imprisoned in 2004.
Upon Larbi's release last year, he went into hiding with militants in Algeria's scrubland, the official said.
Algerian newspapers El Watan and L'Expression reported similar background details about the bombers.
Insurgents battling Algeria's government have largely focused on symbols of the military-backed government and civilians. The strike against the U.N. office signaled a change in tactics.
Marie Heuze, chief spokeswoman for U.N. offices in Geneva, said the latest casualty list showed 11 U.N. staffers died in the attack and five were still missing.
The head of the U.N. Development Program, Kemal Dervis, was sent to Algiers by Secretary-General Ban Ki-moon and has been meeting with the families of the victims and visiting the injured, deputy U.N. spokeswoman Marie Okabe said.
It was the deadliest single attack against U.N. staff and facilities since August 2003, when the world body's headquarters in Baghdad was hit by a truck laden with explosives. That attack killed 22 people, including the top U.N. envoy, Sergio Vieira de Mello, and was blamed on a group that later affiliated with al-Qaida.
On Wednesday, seven survivors were pulled from beneath chunks of concrete, and one woman was transferred to a hospital where both her legs were amputated, said the chief of the emergency team, Djamal Khoudi.
The U.N. offices are in the upscale Hydra neighborhood of Algiers, which houses many foreign embassies. The U.S. and British embassies stepped up security warnings.
Algeria's insurgency broke out in the early 1990s, when the army canceled the second round of the country's first multiparty elections to prevent likely victory by an Islamic fundamentalist party. Islamist armed groups then turned to force to overthrow the government, with up to 200,000 people killed in the ensuing violence.
Until recently, the insurgency had been dying out, with militants' ranks dwindling after military crackdowns and amnesty offers.
But late last year, the main Algerian militant group changed its name to al-Qaida in Islamic North Africa and began waging larger-scale bombings signs that Islamic fighters were regrouping.