BAGHDAD, Iraq (AP) _ An explosion on a road used by British troops killed four civilians in the southern city of Basra, police said Tuesday, and a Kurdish guerrilla group that had battled the Turkish army for 15 years said it would it would dissolve itself.

Freedom and Democracy in Kurdistan, or KADEK, said it was planning to form a new group that would likely be pan-Kurdish and would pursue Kurdish rights through negotiations.

``KADEK is being dissolved in order to make way for a new, more democratic organizational structure that allows for broader participation,'' the group said in a statement.

Adem Uzun, KADEK representative in Rome, confirmed that the group is disbanding itself. ``We have been talking about a new formation for some time,'' he said.

The group was originally called the Kurdistan Workers Party, or PKK, but changed its name to the Congress for Freedom and Democracy in Kurdistan last year and announced a shift in strategy saying it would peacefully campaign for Kurdish rights.

In Basra, an explosion destroyed two cars on a road frequently used by British troops. Soldiers immediately blocked off access to the site, but Iraqi police said four civilians were killed and three injured in the blast.

The commander of U.S. forces in Iraq, Lt. Gen. Ricardo Sanchez, told reporters Tuesday that although attacks against his troops have increased, the insurgents know ``that from a military point of view, they can't defeat us.''

Sanchez also said that Iraqi police apprehended an ambulance Monday full of explosives, the second time that such a vehicle has been seized in the past two weeks.

He defended the use of aerial bombing in Tikrit and Fallujah over the past five days, saying it was necessary to defeat those who attack coalition forces.

The turmoil in the Kurdish organization comes as the guerrillas face increasing pressure from Turkey and the United States, which both consider the guerrillas as terrorists. The group's main fighting force of some 5,000 is based in the mountains of northern Iraq and is expected to face serious pressure from U.S. and Turkish forces as Washington struggles to bring stability to Iraq.

Turkey and the United States have agreed to a joint plan to combat the group and Turkish Foreign Minister Abdullah Gul said Monday that KADEK fighters clashed with Turkish and U.S. forces Sunday in northern Iraq. There were no reports of U.S. or Turkish casualties.

The statement added that the group's goal would be ``negotiating a peaceful settlement with the dominant nation states.''

The statement gave few other details.

Umut Ardan, a press spokesman for KADEK, said that the guerrillas would soon hold a press conference in northern Iraq. He gave no date or details, but said that the group was looking to form a regional organization.

Turkey, home to some 12 million Kurds, has the world's largest Kurdish minority, but neighboring Syria, Iraq and Iran also have substantial Kurdish populations. Kurds in northern Iraq live in a largely autonomous area.

Some 37,000 people, mostly Kurds, died in nearly two decades of fighting between the autonomy-seeking PKK and Turkish troops

The PKK declared a cease-fire after Turkish forces captured the group's leader, Abdullah Ocalan, in 1999. Ocalan was sentenced to death by a Turkish court and is the sole inmate on a Turkish prison island.

On Monday, U.S. jets dropped three 500-pound bombs in the Fallujah area after three paratroopers from the 82nd Airborne Division were wounded in an ambush. There was no report of casualties from the bombing.

``Neither America, nor the father of America, scares us,'' said one resident, Najih Latif Abbas. ``Iraqi men are striking at Americans and they retaliate by terrifying our children.''

In Mosul, an oil official was wounded and his son killed when assailants opened fire at their car in the northern city Monday, his family said.

Mohammed Ahmed Zibari, the Northern Oil Company's distribution manager, was headed to work when gunmen riddled his car, his brother Nawzat Zibari said. The brother speculated that Zibari was killed by ``terrorists'' because they believed he was cooperating with the Americans.