Authorities imposed an indefinite curfew and the army staged a "flag march" in parts of a city in Indian Kashmir Thursday after police shot dead a Sikh protestor, officials said.

A protestor was killed and another wounded in Jammu city, 300 kilometres (190 miles) south of Srinagar, when police fired at an angry crowd protesting at the removal of posters of a Sikh separatist leader, Jarnail Singh Bhindranwale, by police.

The posters were put up by Sikhs to mark the 31st anniversary of Operation Blue Star, the Indian military's assault on the Golden Temple in Amritsar which was aimed at flushing out militants holed up inside demanding an independent Sikh homeland.

Bhindranwale, a Sikh rebel commander who led an armed movement to create Khalistan in the north Indian state of Punjab, was killed in the operation along with scores of his militant associates inside Sikhism's holiest shrine on June 6, 1984.

On Thursday hundreds of rock-throwing Sikh protestors clashed with police who first wielded batons and later fired in the air to disperse them.

As the clashes intensified, with protestors blocking the main highway in Jammu trying to put up the posters again, police fired into the crowd killing one, a police officer said on condition of anonymity as he was not authorised to speak to the media.

Authorities later sought the army's help to prevent the clashes from spreading to other areas.

Troops carried out a "flag march" after "the district administration had requisitioned the army to instil confidence in the people," army spokesman Manish Mehta said in a statement.