NEW DELHI, Oct. 15 (Xinhua) -- At least 20 people were killed Tuesday after a private bus carrying them caught fire in the western Indian state of Rajasthan, officials said.

The moving bus caught fire on the road near Thaiyat village in Jaisalmer district, about 548 km west of Jaipur, the capital city of Rajasthan.

Officials said the bus carrying 57 passengers was on a highway when smoke began emerging from the rear portion. The driver stopped the bus, but within no time the bus was engulfed in flames, trapping the passengers on board. The condition of some of the injured was stated to be critical.

The cause of the fire was not immediately known. However, police suspect a short circuit inside the vehicle might have triggered the blaze. ■