LOKOJA, Nigeria (Reuters) - Nigeria's worst flooding in decades has displaced more than 10,000 people in the centre of the country over the past week and stranded some villagers on rooftops, emergency services said on Thursday.

At least 140 people have been killed around Nigeria and tens of thousands have been forced to abandon their homes since the beginning of July, officials say. The flooding has been the worst for more than 50 years, according to Yushua Shuaib, a spokesman for the National Emergency Management Agency (NEMA).

"Over 10,000 people are displaced completely from their houses in my area and the numbers are increasing," NEMA's coordinator for central Nigeria, Ishaya Chonoko, said by phone. "In some parts, like Ibaji, the entire local government area is submerged by water. People are living on top of their roofs."

Emergency services were trying to access displacement camps -- in some cases by boat -- to hand out emergency items, he said. Worst affected was Kogi state.

Nigeria, which gets heavy tropical rains from May to September, suffers from seasonal flash floods. These are sometimes lethal, especially in rural areas or overcrowded slums.

"I've been here all night and there's nothing to eat," Adamu Musa told Reuters by a flooded highway holding his stranded vehicle outside the central Nigerian city of Lokoja.

(Reporting by Afolabi Sotunde; Writing and additional reporting by Tim Cocks in Lagos. Editing by Jason Webb.)