Nigeria's Christian president has called for calm in his country after Muslim protestors broke out in violent riots leaving several people dead, following his re-election.

In a televised address to the nation late Monday, President Goodluck Jonathan said that "nobody's political ambition is worth the blood of any Nigerian."

Many Muslims claim there was electoral fraud in Jonathan's victory. But officials say this was Nigeria's fairest election in decades.

Election chairman Attahiru Jega announced results Monday night that showed Jonathan won 22.4 million votes, compared to the 12.2 million votes of his nearest rival, the former military ruler Buhari.

In the northern town of Kano, Rev. Lado Abdu said three churches had been set ablaze by angry demonstrators. An armed mob at a bus station also threatened another evangelical pastor before a Muslim man nearby spirited him to safety.

"What brought together religion and politics?" Rev. Habila Sunday said in the local Hausa language. "I want to know why when politics happen, do they burn churches?"

The Nigerian Red Cross said Tuesday that nearly 400 people had been wounded.

Thousands have been killed in religious violence in the past decade in Nigeria, which is Africa's most populous nation.