Algiers - Two car bombs, one of which targeted the U.N. refugee agency's offices, killed at least 45 people including 10 UN staff members Tuesday, authorities said.

Jean Fabre of the UN Development Program said it was still unknown who died or which UN agencies they represented. Fabre said he received the information from Marc Destanne De Bernis, the agency's top official in the Algerian capital.

The explosion occurred around 9:30 am and blew off the front of the UN refugee agency building, said UNHCR chief spokesman Ron Redmond. It apparently caused even worse damage to the main UN building housing the UN Development Program and other agencies diagonally across the street.

Tuesday's attack recalled the Aug. 19, 2003, attack on UN headquarters in Baghdad with a truck bomb that killed top UN envoy Sergio Vieira de Mello, and 21 others.

The civil protection agency said one attack killed 30 people Tuesday and that a second blast left another 15 people dead.

Public radio, Algiers Network 3, said the two bombs went off about 10 minutes apart. Some victims of one of the attacks had been riding a school bus, the official news agency APS said.

Although there were no immediate claims of responsibility, suspicions quickly focused on the North African wing of al-Qaida.

The date -- the 11th -- could point to an Islamic terror link. Al-Qaida in Islamic North Africa claimed responsibility for attacks on April 11 that hit the prime minister's office and a police station, killing 33 people.