At least three people were killed and five seriously injured when gunmen in camouflage fatigues opened fire on villagers in India's restive northeastern state of Manipur, officials said on Tuesday, as sporadic violence continued in the region.

At least 180 people have died since fierce fighting broke out between members of the majority Meitei and minority Kuki communities in the state in May, following a court order suggesting privileges granted to Kukis also be extended to Meiteis.

The latest violence was reported from the Lilong area of Thoubal district on Monday when the group in camouflage fatigues opened indiscriminate fire on locals.

"Three people died of bullet wounds while five others are in hospital with multiple injuries," a senior police official told Reuters by phone.

There was no immediate word on the identities of the victims or the suspected identities of the assailants.

Authorities have re-imposed an indefinite curfew in Thoubal district and four other adjoining districts of Imphal East, Imphal West, Kakching and Bishnupur since Monday night.

Manipur, bordering Myanmar, is among the smallest states in India with a population of 3.2 million people.

Of its residents, 16 percent are Kukis, who live in the hills and receive economic benefits and quotas for government jobs and education, while 53 percent are Meiteis, who control the more prosperous lowlands.