The blaze erupted in an alleyway near the mausoleum of Imam Hussein, the focal point of commemorations for one of the holiest dates in the Shiite calendar.

"According to preliminary reports, the fire was sparked by a gas bottle in the kitchen" of a refreshment tent set up for pilgrims and then spread into an adjacent market, an emergency services statement said.

Fire crews arrived on the scene and put out the blaze "in record time, despite the difficulty of moving fire trucks through the crowds of pilgrims", it added.

Ashura commemorates the martyrdom of the Imam Hussein, grandson of the Prophet Mohammed, in a seventh century battle.