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Worshippers run for their lives seconds after blast at Afghan shrine

Najibullah Musafer / Reuters

People react seconds after a suicide blast targeting a Shiite Muslim gathering in Kabul, Afghanistan, on Dec. 6, 2011.

Massoud Hossaini / AFP - Getty Images

Men run away after an explosion during a religious ceremony in Kabul on Dec. 6, 2011.

NBC News, msnbc.com staff and news services report: 

A suicide bomber attacked a Shiite Muslim shrine in central Kabul, where a crowd of hundreds had gathered Tuesday for the festival of Ashoura, killing at least 54 people and injuring dozens more in an unprecedented sectarian attack.

The attacker blew himself up in the midst of a crowd of men, women and children. The mosque had been packed with worshippers and many who could not fit inside were outside the building.

Afghanistan has a history of tension and violence between Sunnis and the Shiite minority but while such attacks have become commonplace in neighboring Pakistan and parts of the Middle East such as Iraq, they have not previously occurred in Afghanistan.

Click here to continue reading and for the latest updates on the attack.

See more images in the slideshow Afghanistan: Nation at a crossroads.

Najibullah Musafer / Reuters

A man carries a wounded boy after a suicide blast targeting a Shiite Muslim gathering in Kabul on Dec. 6, 2011.

Omar Sobhani / Reuters

A woman mourns after a suicide attack in Kabul on Dec. 6, 2011.