Lagos - More than 100 000 people have had to flee their homes after heavy rains and flooding in Nigeria's southeastern Benue state, President Muhammadu Buhari said late on Thursday."I have received with great concern reports of the flooding in Benue State, displacing, from early estimates, more than 100 000 people," Buhari wrote on Twitter.Helen Teghtegh, the head of a local NGO, the Community Links and Human Empowerment Initiative, said the region had been battered by heavy rains over the past two weeks with the level of the Benue river rising.Many residents in the state capital Makurdi have fled their homes since Wednesday, she added, launching an appeal for donations."We are still trying to get accurate data, we don't know the number of casualties, but we are having a meeting tomorrow with local groups and emergency services, so we should know better," she said.Photographs of inundated Makurdi began spreading on social media Thursday, showing cars and thousands of homes completely submurged. Others showed men and women carrying mattresses, bags and other belongings as they fled on foot.Buhari said he had called for the National Emergency Management Agency to step in, following criticism in the media of authorities' inaction in tackling the flooding.Two camps have been set up in Makurdi to accommodate those made homeless, but they were not set to open before the weekend.Benue state, which is heavily reliant on its agricultural sector, has suffered repeated floods in recent years, caused by heavy rains and the opening of dams in neighbouring Cameroon.In 2012, Nigeria suffered disastrous floods across 30 of its 36 states. Hundreds of people died, and some two million people were left homeless.