Police in Bangladesh have begun an investigation into a bomb blast at a village festival, which killed seven people.

The explosion happened during a crowded weekend carnival in the sub-district of Shakhipuir in Tangail district, some 70 kilometres north of the capital, Dhaka.

Police said four people died at the scene and three others died later in hospital.

Nearly 100 people have died in Bangladesh over the past three years in politically-motivated bombings at rallies and other gatherings.

From the newsroom of the BBC World Service