KABUL, Afghanistan – Police shot four protesters to death Wednesday to stop hundreds from marching on a southern U.S. military base, and Islamic organizations called for an end to deadly rioting across the Muslim world started by drawings of the Prophet Muhammad.

“Islam says it’s all right to demonstrate but not to resort to violence. This must stop,” said senior cleric Mohammed Usman, a member of the Ulama Council – Afghanistan’s top Islamic organization.

“We condemn the cartoons but this does not justify violence. These rioters are defaming the name of Islam.”

Other members of the council went on radio and television Wednesday to appeal for calm. The appeal followed a statement released Tuesday by the United Nations, European Union and the world’s largest Islamic group urging an end to violence.

“Aggression against life and property can only damage the image of a peaceful Islam,” said the statement released by Ekmeleddin Ihsanoglu of the Organization of the Islamic Conference, U.N. Secretary-General Kofi Annan and the EU chief Javier Solana.

In Baghdad, Iraq’s top Shiite political leader criticized attacks on foreign embassies by Muslims.

“We value and appreciate peaceful Islamic protests,” said Abdul Aziz al-Hakim.

“But we are against the idea of attacking embassies and other official sites.”

President Bush called upon governments Wednesday to stop the violence and protect the lives of diplomats overseas.

“We reject violence as a way to express discontent with what may be printed in a free press,” Bush said after meeting with King Abdullah II of Jordan, who asked demonstrators to “express their views peacefully.”

Meanwhile, a U.S. military spokesman said the United States and other countries were examining whether extremist groups may be inciting protesters to riot around the world over the cartoons that have been printed in numerous European papers.

Hundreds rioted outside the U.S. military base in the southern city of Qalat on Wednesday, throwing rocks at Afghan police. Police tried to clear the crowd by firing into the air, then were forced to fire into the crowd, provincial police chief Ghulam Nabi Malakhail said.

Four people were killed and at least 20 were wounded, he said.

The protesters then set fire to three fuel tankers waiting to deliver gas to the base, Malakhail said. He said U.S. troops fired warning shots into the air.

A U.S. military spokesman, Lt. Mike Cody, said he had no details on the incident.

11 people have been killed in the past week as thousands have protested in a dozen Afghan cities and towns to march against the cartoons, which have been reprinted in various European media after first appearing in a Danish newspaper in September.