"No one lives who insults the Prophet," the protesters chanted, a day after Gillian Gibbons, 54, was sentenced to 15 days in jail and deportation.

At least 600 protesters waved green Islamic flags, shook their fists or waved ceremonial swords, and chanted religious and nationalist slogans after leaving Muslim Friday prayers.

The demonstrators made their way to Khartoum's presidential palace for a rally. Others burned newspapers that contained pictures of the teacher.

But they steered clear of Unity High School, where Gibbons worked. The school was guarded by five truckloads of police in riot gear.

Under Sudan's penal code, Gibbons could have faced 40 lashes, a fine or up to a year in jail.

Teachers at the school say that calling the teddy bear Mohammad was not Gibbons's idea. They say no parents objected when she sent them circulars about a reading project that included the bear, introduced to the class in September, as a fictional participant.

Britain's foreign minister said he was "extremely disappointed" with the verdict and called in the Sudanese ambassador for an immediate explanation.