A wooden boat carrying students returning from state exams has sunk in central Democratic Republic of the Congo, killing at least 20 people, authorities said.

The vessel sank as it entered the confluence of the Sankuru and Kasai rivers in Kasai province on Friday, according to witnesses.

Deadly boat disasters are common in the central African country, where night-time travel and overcrowded vessels are often blamed. Poor safety standards and a lack of infrastructure in remote areas have contributed to hundreds of deaths in recent years.

“There were 80 survivors and 20 bodies,” said Francois Kabula, administrator of Ilebo territory in Kasai province.

However, Tshikudi Jean, who witnessed the sinking, told the AP news agency that the boat was carrying more than 200 people.

“The shipowners in the DRC are only after money and don’t care about human lives,” said Francois Malepo, president of the Ilebo civil society organisation.