Authorities dispatched paramilitary police Thursday to a central Nigeria state where residents reported bloody land disputes have left at least 20 people dead and sent others fleeing.

A Nigerian woman sits with her child on Kano street in Lagos, Nigeria April 13, 2006. Nigeria's National Poverty Eradication Programme is campaigning to pull the nation's rural population from the clutches of poverty at a time when most Nigerians still live on less than $1 per day. Picture taken April 13, 2006. [Reuters]

Clashes between the Pan and Gomai people erupted earlier this week over land ownership around Namu, a town in the central Plateau state, and continued for two days, said resident John Yusuf.

"More than 20 people were killed and people are still fleeing the area," Yusuf said by phone from the nearby town of Shendam, where he said he fled with his family. Other residents said many more died in the violence.

Plateau state Gov. Joshua Dariye ordered a nighttime curfew and residents said police reinforcements were arriving Thursday as fighting calmed.

Hundreds of people died in Muslim-Christian violence in the same area in May 2004, but the latest violence has been linked to the land dispute between the Pan and Gomai ethnic groups. Both groups include Christians and Muslims.

Similar clashes between the two ethnic groups last year killed 10 people and prompted an official government inquiry. Rumors that investigators had ruled in favor of the Pan triggered the latest violence, residents said.

Land rights are increasingly important in Nigeria as drought and poor environmental practices spreads the Sahara Desert southward, pushing nomadic herdsmen into wetter farming regions where their livestock eat crops ¡ª fanning tensions.

More than 10,000 people have died in violence since a brutal Nigerian military regime ended in 1999 and democracy allowed greater freedoms but also uncorked long-quelled animosities. Some 3 million people have been left homeless in violence.