Thousands of Shia Muslims gather at the Imam Husayn Holy Shrine in Karbala, Iraq, on Wednesday, July 17, to observe the Day of Ashura.

The crowds are seen both inside and outside the shrine, with those participating wearing black clothing to symbolise mourning.

Ashura is celebrated on the 10th day of Muharram, which is considered to be one of the most sacred months.

It honours the death of Husayn Ibn Ali, grandson of the prophet Muhammed, and 72 companions during the Battle of Karbala in 61 AH (10 October 680 AD).