BEIRUT (AP) — The Latest on the Ashoura holiday (all times local):

4:10 p.m.

Iraqi security officials say at least 12 people have been killed when part of a walkway collapsed during Ashoura commemorations in the Shiite holy city of Karbala.

The officials say 50 others were injured in Tuesday's incident, which happened toward the end of the Ashoura procession, causing panic and a stampede. The officials spoke on condition of anonymity because they were not authorized to give official statements.

Tens of thousands of people converge on the holy city for the occasion, one of the most sacre religious holy days for the Shiite sect.

The somber day of Ashoura commemorates the killing of the Prophet Muhammad's grandson, the Imam Hussein, by a rival Muslim faction in Karbala in present day Iraq, in 680 A.D.

By Qassim Abdul-Zahra.

11:10 a.m.

Shiite Muslims around the world are observing Ashoura, one of the most sacred religious holy days for their sect.

Hundreds of thousands of people in Iraq, Iran and Lebanon are marking the day with rallies, prayers and self-flagellation.

Ashoura commemorates the killing of the Prophet Muhammad's grandson, the Imam Hussein, by a rival Muslim faction in Karbala in present day Iraq, in 680 A.D.

Hussein and his descendants are seen by Shiites as the rightful heirs to the prophet. Hussein's killing has been is attributed with cementing the schism between Shiite and Sunni Islam.

This year's somber commemoration comes amid rising tensions in the Middle East and the crisis between Iran and the U.S. in the wake of the collapsing nuclear deal between Tehran and world powers.