Women activists carry posters at a gathering protesting against ethnic violence in Manipur, in Kolkata, India, on Wednesday. AP

Modi's Bharatiya Janata Party (BJP) has a clear majority of 301 members in the 542-seat lower house of parliament, so the no-confidence vote will not affect its stability.

The opposition instead wants to trigger a debate about violence in the remote, BJP-ruled Manipur state, where more than 130 people have been killed and 60,000 displaced since it began in early May.

Approving the opposition motion, lower house speaker Om Birla said he would soon decide when the debate and vote would take place.

The ethnic tensions in the small state of 3.2 million people are seen as a rare security and political failure by Modi's government, which will face a national election by May 2024.

Further incidents of arson and the destruction of some abandoned houses, government offices and vehicles by armed mobs were reported from at least two districts of Manipur on Wednesday, a local police official said, asking not to be named.

Modi had not commented in public about the violence until last week, when videos showing two women being paraded naked and molested by a mob in Manipur sparked national outrage. Modi condemned the mass assault as "shameful" and promised tough action against the perpetrators.

Opposition parties have, however, disrupted the monsoon session of parliament, which began last week, to demand a detailed statement by Modi on Manipur in parliament, followed by a debate.

As head of the government, he will have to respond to the no-confidence motion before it is put to vote. The government has offered a statement from Home Minister Amit Shah, saying internal security is his ministry's responsibility.

The violence began on May 3 after a court ordered the state government to consider extending special economic benefits and quotas in government jobs and education enjoyed by the tribal Kuki people to the majority Meitei population as well.

Shashi Tharoor, a leader of the main opposition Congress party, said the government must invest time to answer questions about Manipur.

"Everyone knows that Manipur has witnessed horrendous loss of lives in violence, sexual assault and displacement. How can this not be the main agenda?" Tharoor told Reuters.