A rain-swollen river collapsed a bridge in northern India on Thursday, washing away 30 soldiers who were working on the span, an official said.

All the soldiers were feared drowned in the river that snakes through the foothills of the Himalayas, Deputy Commissioner of Himachal Pradesh's [Images] Kinnore Amandeep Garg said.

The soldiers were rebuilding a bridge damaged in June by monsoon floods in Kinnore, about 180 kilometers north of Simla.