The BBC says dozens of people are missing and feared dead after a piece of a Himalayan glacier fell into a river and triggered a huge flood in northern India.

The floodwaters reportedly burst open a dam and a deluge of water poured through a valley in the state of Uttarakhand.

Villages have been evacuated, but officials warned more than 125 people may have been caught in the torrent.

Uttarakhand police said the avalanche struck at about 11:00 local time (05:30 GMT), destroying a dam known as the Rishiganga Hydroelectric Project.

Police said the impact catapulted water along the Dhauli Ganga River, damaging another power project downstream in the Tapovan area.

Uttarakhand Chief Minister Trivendra Singh Rawat said 125 people were confirmed missing so far, but that number could rise.

"Seven bodies have been recovered from the site and rescue operations are going on," Mr. Singh Rawat told reporters at a briefing on Sunday, according to the BBC.

Most of those missing were workers at the two power projects swept away by the deluge.

According to Reuters, Vivek Pandey, a spokesman of the Indo-Tibetan Border Police Force, said 30-35 workers were believed to be inside the tunnel and that rescuers were trying to open its mouth and get inside.

There had been no voice contact yet with anyone in the tunnel, another official said.

On Sunday 12 people were reportedly rescued from another tunnel.

Prime Minister Narendra Modi said he was monitoring the situation. "India stands with Uttarakhand and the nation prays for everyone's safety there," he wrote on Twitter.