ABUJA, Nigeria (AP) — The death toll in the boat accident in north-central Nigeria’s Niger State has risen to 28, emergency services said Monday, as communities mobilized in support of an intensified search for dozens still missing after the passenger boat capsized.

The boat capsized along the Niger River on Sunday morning with more than 100 villagers, mostly women and children, aboard. They were traveling to their farmlands in the Gbajibo community, located 251 kilometers (156 miles) from the state capital Minna, the closest source of emergency response.

It took several hours before help could reach the community because of its remote location, and villagers nearby were on the lookout for bodies floating on the river, Niger State Emergency Management Agency spokesman Ibrahim Audu told The Associated Press.

Divers recovered four more bodies from the river by Monday morning with at least 40 passengers believed to be still missing, Audu said. Thirty had been rescued.

“Instruction has been passed across all the communities surrounding that place so that some of them will watch out (for bodies),” he said.

Niger Gov. Mohammed Umaru Bago described the accident as “shocking and sorrowful” and directed the state emergency services to assist those affected, according to a statement issued by his office. He reiterated the importance of using life jackets and avoiding overcrowded boats.

Concerns remained about the regular and deadly boat accidents in Nigeria, Africa’s most populous country where a number of remote and riverine communities do not have access to good roads, leaving rivers as the only available means of transportation.

It is still not clear what caused the latest accident but emergency services personnel said it could be as a result of overloading, the condition of the boat or a hindrance of the boat’s movement along the water.