Samastipur | Four persons, including a woman, were injured in a blast inside a train at Bihar's Samastipur railway station when gunpowder inside a bag accidentally ignited, a senior official said.

According to Vinay Srivastava, Divisional Railway Manager, Samastipur, the blast took place on Wednesday afternoon when the Bhagalpur-Darbhanga Intercity Express was at Samastipur rail station's outer signal.

A team of RPF and GRP personnel immediately rushed to the affected coach in which smoke was found billowing from a bag kept on an upper berth.

The injured passengers were taken to a local hospital for treatment and the train was allowed to reach its destination at Darbhanga, where all the passengers of the coach were interrogated.

"Two of the passengers, Arvind Mandal and Navendu Mandal, both residents of Madhubani district, admitted to have boarded the train with the bag in which they were carrying gunpowder to make fireworks," the DRM said.

Both have been arrested and further investigation was on, the official added.