Kalimpong, Aug. 17: Three persons were killed and 40 injured when a Sikkim National Transport bus going from Gangtok to Mangan in North Sikkim skidded off the road and rolled down a hill at Ambithang, less than a kilometer short of Mangan, today.

Sikkim transport secretary S.B.S. Bhaduria said: "Preliminary report suggests that the bus fell down a hillside while giving pass to another vehicle," he said. The distance between Gangtok and Mangan is about 50 kms.

The dead have been identified as Praveen Nair, 26, Dhan Raj Limboo, 60, and Ugen Lhendup Bhutia. All the deceased were residents of Sikkim.