Associated Press
Rescuers and forensic police officers work at the site of a bomb blast in Algeria. Sixty or more people may have died.

ALGIERS, Algeria — Twin car bombs near U.N. offices and an Algerian government building killed dozens of people Tuesday in what may have been the deadliest attack here in more than a decade.

Two European diplomats in Algiers said that reports from rescue and medical workers led them to believe that 60 or more people had died. The Algerian interior minister, Noureddine Yazid Zerhouni, told reporters at a news conference Tuesday evening that so far only 22 had been confirmed dead.

The terrorist group Al-Qaida in the Islamic Maghreb claimed responsibility, posting a message on Islamist Web sites with photographs of two men it said were suicide bombers who carried out the attacks, which it said were aimed at "the Crusaders and their agents, the slaves of America and the sons of France."

Some of the dead were students aboard a bus that was on its way to a university when it was struck by the first car bomb.

Marie Okabe, the deputy spokeswoman for U.N. Secretary-General Ban Ki-moon, said that preliminary figures showed that at least eleven U.N. staff members had died and that the organization was trying to account for several others who were missing.

The first bomb exploded shortly before 9:30 a.m. outside Algeria's Constitutional Council in the Ben Aknoun neighborhood. The council oversees the country's elections. The bomb stripped away the facade of the white Moorish-style building, which had only recently been built by a Chinese construction company. The bus carrying the students who were killed was on its way to the nearby Ben Aknoun university campus when the explosion occurred.

The bomb near the U.N. building exploded about 10 minutes later on narrow Emile Payen Street, collapsing much of the United Nations' white multistory building and hurling chunks of rubble across the street. It left the roadway carpeted for blocks with shattered glass.

The organizations housed in the damaged building include the U.N. Development Program, the World Food Program, the Population Fund, the International Labor Organization, the Industrial Development Organization as well as the Safety and Security Office and the Public Information offices.

The message posted by Al-Qaida in the Islamic Maghreb identified one of the men it said was a bomber as Ibrahim Abu Uthman, who had a gray moustache and appeared to be in his 50s. The second, identified as Abdul Rahman Abu Abdul Nasser Al-Aassemi, was younger and smiling.

The message said each detonated a truck containing over 800 kilograms of explosive material.