ABUJA: Nigeria on Thursday warned tens of thousands of people living along one of its main rivers to expect massive flooding as neighboring Cameroon announced plans to release water from a dam.

The National Emergency Management Agency (NEMA) said it had been informed that the Lagdo dam in northern Cameroon would be emptying water into the River Benue until November to relieve an excessive build-up.

The opening of the dam as well as heavy rain in 2012 led to huge flooding along the river, the main waterway in eastern and central Nigeria.

Authorities in northeastern Adamawa state said at least 30 people had been killed and 120,000 displaced, while more than a dozen Cameroonians were reported to have died.