Provide the highlights for the following article:\n    ALGIERS, Algeria (CNN) -- Rescuers are sifting through the rubble of the United Nations headquarters in Algiers hoping to find survivors after a powerful bomb ripped off the building's facade and leveled nearby U.N. offices. Rescuers and bomb experts search for survivors in the rubble of a destroyed building. It was one of two suspected car bombs that struck Algiers within 10 minutes of each other. The death toll is unclear: the official government count is at least 26, but hospital sources in Algiers told CNN affiliate BFM-TV that 76 people were killed in the two blasts. A statement from the United Nations said 45 people were reported killed. Algerian Interior Minister NAME_1 blamed a militant Islamic group with ties to al Qaeda for the attacks, which also targeted a building housing Algeria's Constitutional Council and Supreme Court. In a posting on an Islamist Web site, the group al Qaeda Islamic Maghreb claimed responsibility. CNN could not immediately corroborate that claim, but the Web site is known to carry messages, claims and videos from al Qaeda and other militant groups. In the posting, the bombers were identified as NAME_2 and NAME_3 Abdel Nasser al-Asimi. It said two trucks were filled with \"no less than 800 kg (1,763 pounds) of explosives.\" The group called the operation \"another successful conquest and a second epic that the knights of faith have dictated with their blood, defending the wounded Islamic nation and in defiance to the Crusaders and their agents, the slaves of America and the sons of France.\" At least 10 U.N. staffers were among those killed, according to U.N. spokeswoman NAME_4. The offices of the UN High Commissioner for Refugees -- located across the street from the U.N. headquarters -- were leveled by a blast that struck about 9:30 a.m. (3:30 a.m. ET) Tuesday. \"Our offices are basically destroyed now, nothing works,\" UNHCR spokesman NAME_5 said from its Geneva headquarters. Watch his full interview . He said rescuers are working into the night trying to get to the trapped U.N. workers. \"It's a very serious situation still with the U.N. in Algiers,\" he said. In a strongly worded statement, U.N. Secretary-General NAME_6 condemned what he called \"an abjectly cowardly strike against civilian officials serving humanity's highest ideals under the U.N. banner.\" \"The perpetrators of these crimes will not escape the strongest possible condemnation -- and ultimate pu Your response should contain 600+ words.
user