At least 30 people have died in a suicide attack targeting Shia in Iraq’s capital Baghdad, officials say.
More than 60 were injured in the attack, on a tent in a crowded market in a northern district of the city.
Many Shia pilgrims are taking part in mourning rituals commemorating the killing of the Prophet Mohammed’s grandson, Hussein, in the 17th Century.
No-one claimed the attack, though so-called Islamic State (IS) have carried out similar attacks in the past.
Reports say a militant detonated a suicide vest in the tent at lunchtime, when it was full of pilgrims.
BBC Middle East editor Sebastian Usher says Sunni militants have long used such pilgrimages as targets for attacks causing large scale casualties.
This year, IS revived its bombing campaign in Baghdad killing hundreds of people, in what is seen as a response to the group’s loss of much of its territory in Iraq.
The latest attack comes as Iraqi forces prepare for an offensive in northern Iraq on Mosul, the last IS-held major city in the country.