At least 80 people have died after a boat sank in Democratic Republic of Congo, the country's president has said.

The disaster happened on Wednesday on the Kwa River, 70km (44 miles) from the town of Mushie in the province of Maï-Ndombe near the border with neighbouring Congo-Brazzaville.

In a statement on social media, President Félix Tshisekedi said he was "devastated".

The president said those affected would receive help and also ordered an investigation into what caused it.

"The President of the Republic is calling for an investigation into the true causes of this unfortunate incident, to prevent such a disaster from happening again in the future," the presidency said on X, formerly Twitter.

Deadly boat accidents are common in DR Congo, where boats are frequently overcrowded with passengers who are rarely given safety jackets and often cannot swim.