Over 30 people were feared killed and 15 were seriously injured when armed separatists ambushed a military convoy in the eastern Indian state of Manipur early on Friday, the Indian news agency PTI reported.
It quoted official sources as saying that at least 25 people were believed to have died when an Indian Reserve Battalion (IRB) bus in the ambushed five-vehicle convoy fell into a gorge 1,000 feet deep.
The first official reports on the incident said six people were killed on the spot and 15 others received serious bullet wounds.
All 21 casualties were IRB personnel.
The convoy was travelling from Thanlon when it was attacked in Churachandpur District.
Official sources said the ambush was the biggest of its kind in Manipur in recent years.
BBC Monitoring (http://www.monitor.bbc.co.uk), based in Caversham in southern England, selects and translates information from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages.