It is also likely that the bodies of Christians killed in the riots were taken elsewhere, making the total number of dead uncertain.
Thousands flee fighting
The Red Cross said around 7,000 people had fled their homes and were sheltering in government buildings, an army barracks and religious centres.
A senior police official told the Reuters news agency that five neighbourhoods had been hit by violent clashes and that 523 people had been detained.
The riots were sparked after electoral workers failed to publicly post results of local elections held on Thursday.
Homes, churches and mosques were burnt down in the rioting fuelled by rumours that the All Nigerian Peoples Party (ANPP) had lost the elections to the ruling People's Democratic Party (PDP).
The ANPP is considered a predominantly Muslim party, while the PDP is mainly Christian.
The violence is the worst since Umaru Yar Adua's inauguration as Nigeria's president in May 2007. Adua came to power following a vote that international observers dismissed as not credible.
Few Nigerian elections have been deemed free and fair since independence from Britain in 1960, and military takeovers have periodically interrupted civilian rule.
Jos, the administrative capital of Plateau state, had also been the scene of a week of violence between Christians and Muslims in September 2001, which also left hundreds dead.