Police in riot gear used batons and fired teargas to disperse Shiites in Srinagar, the summer capital of Indian Kashmir, a police officer said, asking not to be named as he was not authorised to speak to media.
"We also used water cannon to spray protesters with blue dye," the officer said, accusing the marchers of defying a ban on processions in Kashmir.
Shiite Muslims throughout the world stage processions and hold rallies during Muharram, the first month of the Islamic Hijra calendar, to mark the anniversary of the death of a grandson of the Prophet Mohammed.
Authorities have forbidden most processions in Kashmir since the outbreak of insurgency against Indian rule in 1989 on grounds that the emotional religious rituals could be used by separatists to stoke anti-India sentiment.
They allow only small mourning rallies and processions in areas with sizeable Shiite populations, leading to annual friction between police and mourners.
"We had to detain some three dozen mourners for defying the ban (on procession)," the officer said, adding nearly two dozen mourners and policemen were hurt during ensuing clashes.
Police blocked hundreds of marchers at several places in Srinagar as they whipped themselves to mourn the death of the Prophet`s grandson.
Srinagar`s main commercial hub of Lal Chowk was sealed with barbed wires and armoured police vehicles, witnesses said.
The insurgency has left more than 47,000 people dead by official counts since 1989. Human rights groups put the toll at 70,000 dead and missing. (*)