BAGHDAD (AP) A walkway collapsed and set off a stampede in the holy city of Karbala on Tuesday as thousands of Shiite Muslims marked one of the most solemn holy days of the year. At least 31 people were killed and about 100 were injured, officials said.

It was the deadliest stampede in recent history during Ashoura commemorations, when hundreds of thousands of people converge on the city, some 80 kilometers (50 miles) south of Baghdad, for the occasion every year.

The stampede happened toward the end of the Ashoura procession, causing a panicked rush among worshippers near the gold-domed Imam Hussein shrine, according to two officials who spoke to The Associated Press from Karbala.

Afdhal al-Shami, a shrine official, denied that there was a collapse or any cracks in the walkway. It was a stampede that led to this incident, he said.

Mohammed Shenin Jebir, a pilgrim, said everything happened very suddenly.

Visitors suddenly fell on the ground and there was a strong stampede, there were many pilgrims who all fell on top of each other, he said, speaking after being treated at the Hussein Medical City in Karbala for cuts and bruises above his right eye.