A boat capsized on a river in Democratic Republic of Congo killing at least 140 people, the provincial governor's office said Thursday.

The boat overturned on the Kasai river, a tributary of the Congo river, in the west of the country on Wednesday.

"I can confirm the accident. We're currently in a crisis meeting," said a source in the Bandundu province governor's office who asked not to be named.

The source said there were 140 dead.

The boat was carrying passengers and goods from Mushie, about 30 kilometres from Bandundu, the province's chief town.

River transport is widely used throughout DR Congo, where the numerous waterways include the 4,700 kilometres long Congo river.

Scores of people are killed each year though in river disasters involving overcrowded boats.

In November last year, at least 73 people died when two linked barges sank on Mai-Ndombe lake in Bandundu province.

In September 2009, more than 250 people died in three boat accidents on Congolese waterways.