The region's Nepali-speaking Gorkha community has since last month held protests demanding a separate state, Gorkhaland, within India to protect their Himalayan culture. They have regularly clashed with the police. Seven civilians have died while dozens of security personnel have been injured.

The eastern state of West Bengal, where the tea-growing region of Darjeeling is located, has deployed troops to keep the peace, the second time in three weeks, an army spokesman said.

The killing on late Friday of 31-year old Tashi Bhutia, a supporter of Gorkha National Liberation Front (GNLF) - one of the two political parties leading the protest - led to escalation of the violence in the tourist town.

A senior police officer in Darjeeling said Bhutia might have been killed in a cross firing when security forces were attacked. The officer did not wish to be named.

The protesters also torched Sonada railway station - a UNESCO-listed heritage site - while sporadic incidents of violence in various other parts of the town ensued.

The unrest in the region has also hurt economically with trade and business completely shut down and disrupting exports of "second flush" tea crop, one of the world's most expensive tea exclusively produced in Darjeeling.

At least 1,200 people died during the first Gorkhaland protests in the 1980s.