Prime Minister Nouri al-Maliki on Friday ordered a nationwide freeze on raids against suspected Shiite militants after the leader of the biggest militia complained that arrests of his followers were continuing despite his order to pull his fighters off the streets.

Also Friday, a homicide bomber killed at least 15 people and wounded eight when he blew himself up during a funeral for a policeman north of Baghdad, officials said. Such attacks are the hallmark of Sunni religious extremists.

Al-Maliki's statement did not give a timeframe for the freeze nor refer to the Mahdi Army of Shiite cleric Muqtada al-Sadr. The statement said only that the freeze was designed to give a chance to "those who repented and want to lay down their arms."

"Those who lay down their arms and participated in the recent acts of violence will not be prosecuted," the statement said.

On Thursday, the prime minister said he intended to launch security operations militants in two Baghdad neighborhoods where the Mahdi militia operates, including its Sadr City stronghold.

Many residents of Shiite neighborhoods stocked up on food and other supplies after al-Maliki's statement.

The homicide attack occurred in Sadiyah, a town 60 miles north of Baghdad in the volatile Diyala province, where U.S. and Iraqi forces are still battling Sunni extremists of Al Qaeda. Police said the bomber mingled among the mourners and then triggered an explosive vest.

The Shiite-led government launched a crackdown March 25 against Shiite extremists in the southern city of Basra, triggering fierce resistance that included rocket and mortar attacks against the U.S.-controlled Green Zone in Baghdad.

Fighting eased after al-Sadr called Sunday on his militia to stop fighting. But al-Sadr has complained that government forces are still conducting raids and arrests against his followers.

A U.S. military statement on Friday said that during the operation Iraqi special forces had captured a suspected militant leader who has been rallying insurgents in Basra to fight against coalition forces.

The statement said the suspect was linked the kidnapping and murder of Iraqi security troopers and had been involved in oil smuggling "and foreign fighter networks." No further details were released.

The government has given Shiite militiamen until Tuesday to hand in heavy weapons, but it was unclear if the freeze was tied to that date.

Despite a drop in fighting, Iraqi officials insist that the Basra crackdown will continue until it breaks the stronghold that armed groups have had on the city since 2005.

Maj. Tom Holloway, a British military spokesman, said a roadside bomb targeted a British force "supporting an Iraqi-led operation at the very fringes of Basra." He said the British were "mentoring and monitoring" the Iraqi operation, but provided no further details.

The action came a day after Iraqi troops killed seven militants and detained 16 in three separate incidents in the same general area.

In a separate firefight, a coalition warplane was used to bomb insurgents engaging Iraqi special forces in the city. The air strike killed two militants, the U.S. statement said.

Iraqi officials have insisted the crackdown is against criminal gangs and not al-Sadr's political movement.

Elsewhere, a roadside bomb early Friday killed four policeman and wounded one in Hillah, a town about 60 miles south of Baghdad, a police spokesman said.