At least 40 people are missing and presumed to have drowned in Nigeria's north-western Kebbi state after a passenger boat capsized in strong currents, a local official has said. Boat accidents are frequent on Nigeria's poorly regulated waterways due to overloaded boats, a lack of maintenance and poor safety, particularly during the rainy season when rivers and lakes swell and flood. “We are still searching for 40 passengers with the help of local divers, and believe they have drowned,” said Bala Mohammed, the administrator of Yauri district, where the accident happened on Monday. “It is a difficult search due to the high water level and strong currents as a result of the rainy season.” Last month, at least 24 bodies were recovered while 50 were missing after a boat ferrying more than 100 farmers across the Niger river in Niger state capsized, officials said. Two days earlier, 10 people drowned while three went missing when a boat ferrying traders overturned in a lake in north-eastern Adamawa state, according to emergency officials.