Sectarian violence in Pakistan on Friday caused authorities to impose a curfew on the northern city of Rawalpindi.
Ten people died after Shia Muslims staged a procession during the religious festival of Ashura.
Another 35 people were injured after the procession passed by a nearby Sunni mosque and violence broke out.
The Taliban have vowed to take revenge on Shias for the deaths.
Xinhua reported that some of the mourners began firing into the air when they passed the mosque.
Gun battles then broke out and press photographers were allegedly beaten during the mayhem.
Sunni worshippers were reportedly dragged from the mosque and killed in the street.
Dozens of shops and a Sunni seminary were burned.
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Mobile phone networks in the city have been jammed and security has been stepped up for the ceremonies in the coming week.
Tens of thousands of soldiers were deployed in the streets ahead of the commemoration.
The curfew is expected to last until tonight.
Ashura is a Shia holiday commemorating the death of Imam Hussein, the grandson of the Prophet Muhammad.
The holiday in Pakistan has been marred by violence and bloodshed in recent years.