A bomb exploded Thursday on a passenger train in northern India (search), killing at least one person and injuring 22, railway officials said.

Medical teams were sent to the scene of the explosion, near the town of Jaunpur in Uttar Pradesh (search) state, about 400 miles east of New Delhi, officials said.

R.K. Singh, the top official for Indian Railways (search), said the explosion had been caused by a bomb but gave no further details. He said one person had been killed and 22 people were injured.

"Train passengers have been evacuated and the train is being searched by railway police," said Rajendra Singh, a railway official.

The train was traveling from the eastern city of Patna to New Delhi when the blast occurred in a crowded passenger car, officials said.