About 120 people are missing and feared dead after a boat capsized on Lake Volta in Ghana. Officials say 30 people have been rescued.

The boat was authorized to carry 70 passengers, but officials say more than twice that number were aboard the vessel when it hit an object under water and sank Saturday.

Officials say rescuers managed to save some people, but that passengers not yet found are feared dead.

Police spokesman Kwesi Ofori said the boat probably hit a stump as it travelled across Lake Volta, which covers 8,500 square kilometers, more than three times the size of Luxembourg.

Ofori said the boat had been travelling from Dudzome, in the Afram Plains region, to Abotoase further east.

The Associated Press reported that the passengers were relocating their homes after the area where they had lived in Dudzome was designated a natural reserve.

Africa is a vast continent with poor road and rail systems. As a result, water routes are often used to transport goods and people, and many Africans rely on sub-standard vessels for travel. Few boats keep proper passenger manifests and the exact death tolls of many accidents are never known.