NEW DELHI: A bomb planted on a bicycle killed four people when it exploded near a school in the Indian state of West Bengal on Thursday, the Press Trust of India reported.

Six other people were injured, several critically, after the bomb went off in Bajrapara district of the state in India's east, the news agency said, quoting police and hospital officials.

Police said the explosive device had been tied to a bicycle but did not name any group or individuals suspected of being behind the blast.

Domestic militant movements have carried out a series of deadly bomb attacks in India in recent months, including an attack in the state of Bihar earlier this month that killed seven police.