CREDIT: Edmond Terakopian, the Associated Press Thousands of Muslims gather in front of Britain's National Gallery yesterday before a large protest over the Prophet Muhammad cartoons in London. Protests continued around the world yesterday, with the worst violence in Nigeria.

MAIDUGURI, Nigeria - Nigerian Muslims protesting caricatures of the Prophet Muhammad attacked Christians and burned churches yesterday, killing at least 15 people in the deadliest confrontation yet in the whirlwind of Muslim anger over the drawings.

It was the first major protest to erupt over the issue in Africa's most populous nation. An Associated Press reporter saw mobs of Muslim protesters swarm through the city centre with machetes, sticks and iron rods. One group threw a tire around a man, poured gas on him and set him ablaze.

In Libya, the parliament suspended the interior minister after at least 11 people died when his security forces attacked rioters who torched the Italian consulate in Benghazi.

Danish church officials met with a top Muslim cleric in Cairo, meanwhile, but made no significant headway in defusing the conflict.

And in what has become a daily event, tens of thousands of Muslims protested, this time in Britain, Pakistan and Austria.

But it was in Nigeria, where mutual suspicions between Christians and Muslims have led to thousands of deaths in recent years, that tensions boiled over into sectarian violence.

Thousands of rioters burned 15 churches in Maiduguri in a three-hour rampage before troops and police reinforcements restored order, Nigerian police spokesman Haz Iwendi said. Mr. Iwendi said security forces arrested dozens of people in the city about 1,600 kilometres northeast of the capital, Lagos.

Chima Ezeoke, a Christian Maiduguri resident, said protesters attacked and looted shops owned by minority Christians, most of them with origins in the country's south.

"Most of the dead were Christians beaten to death on the streets by the rioters," Mr. Ezeoke said. Witnesses said three children and a priest were among those killed.

Meanwhile, Muslims in Calgary and Vancouver yesterday denounced the increasingly violent global reaction to the cartoons. Calgary Muslims held an open house, while in Vancouver a peaceful protest was staged.

Muslims in both cities opposed a call by a Pakistani cleric, who has reportedly offered a $1-million U.S. bounty for killing the cartoonist responsible for the drawings.

"The Muslim Council of Calgary ... considers (the bounty) a blatant insult to Islam, to Muslims and against teaching of the Koran, which condemns the taking of human lives," said spokesman Abdu Souraya.

In Vancouver, Imam Fode of the Zawiyah mosque, told a rally that the international reaction seems to be snowballing out of control.

"I think it is disproportionate -- I do not believe in violence," the imam told a crowd of about 80. "It is blowing things out of proportion. This is the the proper way of dealing with it, not the way it has been dealt with in the Muslim countries."

The Danish cartoons, including one showing Muhammad wearing a bomb-shaped turban with an ignited fuse, have set off sometimes violent protests around the world.

After a Danish newspaper, Jyllands-Posten, printed the caricatures in September, other western newspapers, mostly in Europe, followed suit, asserting their news value and the right to freedom of expression.

But Nigeria has been spared much of the violence seen elsewhere in the world, though lawmakers in the heavily Muslim state of Kano burned Danish and Norwegian flags and barred Danish companies from bidding on a major construction project. Kano lawmakers also called on the state's five million people to boycott Danish goods.

With yesterday's deaths, at least 45 people have been killed in protests across the Muslim world, according to a count by The Associated Press.

In Cairo, Bishop Karsten Nissen, of Denmark's Evangelical Lutheran Church, met with Grand Imam Mohammed Sayyed Tantawi of al-Azhar University, the world's highest Sunni Muslim seat of learning.

Mr. Tantawi said the Danish prime minister must apologize for the drawings, and demanded the world's religious leaders, including Pope Benedict XVI, should meet to write a law that "condemns insulting any religion, including the Holy Scriptures and the prophets." He said the UN should impose the law on all countries.