Dozens of people have been killed in two bomb blasts in the Algerian capital, Algiers. Many are feared trapped in the debris of collapsed buildings.

The first bomb exploded outside the supreme court. A passing bus, full of university students, was ripped apart by the explosion.

The UNDP office in Hydra district bore the brunt of the second blast.

Algerian Interior Minister Yazid Zerhouni said a suicide bomber was responsible for the UN attack.

A UN employee caught up in the second blast told the BBC: "Everything shattered. Everything fell. I hid under a piece of furniture so I wouldn't be hit by the debris."

Crowds of people in the streets initially impeded rescuers' efforts to reach those believed trapped in the rubble.

There has been no immediate claim of responsibility. This is the latest in a series of bombings across the country this year in which scores of people have died.

Correspondents say the targets and the timing indicate that this is likely to be the work of al-Qaeda in the Islamic Maghreb, a group that has claimed many of the recent blasts.