Afghan police said hundreds of people had gathered in the center of the capital for Ashura, the Shi'ite holy day to commemorate the martyr death of Hussein ibn Ali, the grandson of the Prophet Mohammed, who died in the battle of Kerbala in present day Iraq in the year 680.

A spokesman for Kabul police, Hashmatullah Stanekzai, said the massive mid-day blast at the Abul Fazel shrine left at least 54 people dead and dozens more injured.

Shortly afterward, a bicycle bomb exploded near the main mosque in the northern city of Mazar-i-Sharif, killing four people and injuring 17 others.

As in Kabul, the city's streets were filled with people celebrating Ashura, but it was not immediately clear if that attack had also targeted Shi'ite worshippers.

Suicide attacks happen often, despite heavy security

No claims of responsibility

The Taliban could not be reached for comment on either attack, but local authorities suspect they are behind the attacks. Shi'ites were banned from marking Ashura in public under the Taliban.

Ashura is the biggest event in the Shi'ite calendar and the large processions are vulnerable to militant attacks. The holiday has frequently been a source of tension between Shi'ite and Sunni Moslems.

In an incident on Monday, Taliban fighters claim to have killed Afghan policemen and kidnapped 30 others after a pitched battle between security forces and Taliban insurgents near Faizabad in northeastern Afghanistan. The claims are being investigated.

Responsibility for security in the city is scheduled to be transferred soon from German troops stationed in the region to local forces.

Author: Gregg Benzow (dpa, AP, AFP, Reuters)

Editor: Sarah Berning