New Delhi, Oct 29 : Four passengers were injured after an explosion occurred inside a Rohtak-Delhi passenger train injuring four passengers, an official said.

The official said that all four injured passengers have been shifted to hospital for further treatment.

'The Railway Police and local police are inspecting the site along with a forensic team from Delhi to gather essential evidence on how the blast took place,' he said.

He added that the explosion took place near the Sampla station soon after the train departed from Rohtak station.

Eyewitnesses added that the sudden explosion led to a chaotic scene while the train was immediately halted, leaving the passengers in a distressed state.

Reports also suggest that the blast may have resulted from a large quantity of sulfur and potash in a plastic bag, that a passenger was carrying which accidentally ignited and caused an explosion inside the train.

An official said that the authorities are closely monitoring the situation and an investigation into how the blast happened inside the train is underway.

/IANS