A mountain glacier broke in the northern Indian state of Uttarakhand on Sunday, releasing an avalanche of water and mud down a river.

Local authorities say seven hydroelectric dam construction workers were killed in the deluge, with more than 100 others missing.

Military and police personnel say they have rescued 16 people, but they say the number of victims may rise.

Video footage believed to have captured what happened in an area near a hydropower plant shows torrents of muddy water sweeping away equipment and trees.

A nearby resident said it was like a scene from a film.

Prime Minister Narendra Modi tweeted that he is "constantly monitoring the unfortunate situation in Uttarakhand," adding "the nation prays for everyone's safety there."

A team of experts will try to identify what caused the glacier to break off.

 nhk