GUWAHATI: At least 13 people were killed in a gunfight between two unknown militant groups in India’s restive Manipur state on Monday, a police official said, seven months after ethnic clashes in the border state killed at least 180 people.

Their bodies, with multiple bullet wounds, were found in a village in Manipur’s Tengnoupal district where the official said a “massive” gunfight was reported.

The state has witnessed sporadic violence since the peak of ethnic clashes that erupted on May 3 between members of the majority Meitei ethnic group and minority Kuki community over sharing government benefits and quotas.

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The clashes have marked a rare security failure for Prime Minister Narendra Modi’s government in a state ruled by his Bharatiya Janata Party. No weapons were found near the bodies, the senior police official told Reuters by phone from state capital Imphal, requesting anonymity.

“It could be possible the weapons were looted after they were killed,” the official said, adding that they could not immediately identify the dead or the militant groups.