A local official says at least 27 people are dead after a passenger boat capsized along Congo’s Mongala River in the country’s north.

Alpha Belo, head of the locality of Binga, said Wednesday the boat sank nearby overnight Monday. He says at least 30 people survived but proper support was not available to rescue everyone.

Belo says rescuers will continue to search for missing people, but the boat did not have a manifest and it is unclear how many people were on it.

Boats transporting people along Congo’s rivers are often overcrowded, making capsizes common.

Road infrastructure in the vast Central African nation is often poor.