More than 200 people have been killed in two days of clashes between Christians and Muslims in central Nigeria.

The Red Cross has described it as the worst unrest in the country for years.

The army sent reinforcements to enforce a 24-hour curfew on the city of Jos, which lies at the crossroads of Nigeria's Muslim north and Christian south, after rival gangs burned churches and mosques.

About 7,000 people fled their homes and were sheltering in government buildings and religious centres, the Red Cross said.

The governor of Plateau state, of which Jos is the capital, said in a statement that troops had orders to shoot on sight to enforce the curfew in neighbourhoods hit by the violence.

Gunfire and explosions heard in the early hours later died down but many streets were deserted. Military checkpoints were set up around the city and soldiers helped clear bodies from the streets.

A spokesman for Plateau state governor Jonah Jang said hundreds of youths found to be carrying weapons had been arrested at military roadblocks.

Christians and Muslims generally live peacefully side by side in Nigeria but hostility has simmered before in Plateau.

Hundreds were killed in ethnic-religious fighting in Jos in 2001 and three years later, hundreds died in clashes in Yelwa, leading then-President Olusegun Obasanjo to declare a state of emergency.