An explosion on a road frequently used by British troops killed six civilians in southern Iraq, and the top U.S. commander in Iraq said Tuesday that the military detained about 20 people suspected of links to Al Qaeda.

Also, an explosion occurred Tuesday afternoon as U.S. soldiers were escorting 16 Iraqi prisoners from jaiates of plastic explosives and cylanders packed with other explosives, said Col. Kurt Fuller of the 82nd Airborne Division. The makeshift bomb would have done "would completely destroy a building. It's a huge bomb," Fuller said.

Meanwhile, the coalition military commander, Lt. Gen. Ricardo Sanchez (search), said American forces have arrested about 20 people possibly linked to Usama bin Laden's terror network. The detainees are being interrogated, but Sanchez said officials haven't been able to "establish definitively" that they belong to Al Qaeda.

The head of the U.S. administration in Iraq, L. Paul Bremer (search), said in September that coalition forces are holding 19 suspected Al Qaeda members. It was not clear whether Sanchez was talking about the same suspects.

U.S. and Iraqi officials believe that foreign fighters and Islamic miliants have been carrying out attacks in Iraq, parallel to the resistance believed led by loyalists of ousted leader Saddam Hussein. But how many foreign fighters have slipped into the country and how closely they are working with Iraqi guerrillas has been a mystery.

Sanchez said Tuesday that "hundreds" of foreigners cross the border into Iraqi to carry out attacks — including Yemenis, Sudanese, Syrians and Egyptians.

In London, British Foreign Secretary Jack Straw said Tuesday that "considerable effort" was being made to get better intelligence on fighters in Iraq.

Asked in the House of Commons about those responsible for attacks, Straw said, "We cannot tell for certain. Indeed,if we knew for certain dealing with the terrorists would be that much easier."

U.S. officials have said at least some attacks may have been orchestrated by Saddam's former deputy, Izzat Ibrahim al-Douri, who may have forged an alliance with the Kurdish religious extremist group Ansar al-Islam (search), believed to have ties to Al Qaeda.

Meanwhile, about 200 Shiite Muslims rallied briefly Tuesday in the eastern Baghdad neighborhood of Sadr City to protest the shooting death of the chairman of the U.S.-appointed municipal council, Muhanad al-Kaadi, during an altercation with U.S. military guards.

The protest broke up when soldiers ordered the crowd to disperse, participant Ali Mohammed said.

Al-Kaadi was shot Sunday after arguing with a soldier guarding council headquarters, the U.S. military said. The statement blamed it on al-Kaadi's "refusal to follow instructions of the onsite security officer who was enforcing" regulations "in accordance with the rules of engagement."

Al-Kaadi, who spoke fluent English, was trying to improve relations between the Americans and residents of the impoverished community.

Also in Baghdad, the Kurdish rebel group known as the Congress for Freedom and Democracy in Kurdistan (search), or KADEK, said it was planning to form a new group that likely would 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.

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

The turmoil in the Kurdish organization comes as the guerrillas face increasing pressure from Turkey and the United States, both of which consider the guerrillas to be terrorists.

The group's main fighting force of about 5,000 is based in the northern Iraqi mountains and is expected to face serious pressure from U.S. and Turkish forces as Washington struggles to bring stability to Iraq.

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 (search), in 1999.

In Japan, media reports said gnawing concerns about the deteriorating security situation and worries about the political fallout may force Prime Minister Junichiro Koizumi to push back or water down his plans to send a small troop contingent to Iraq.

The Japanese were planning to send 150 soldiers to southern Iraq by Dec. 31 and 550 soldiers early next year to provide water, medical care and other services. Koizumi reportedly hoped to get his Cabinet to sign those orders by week's end.

Koizumi has supported the war before an increasingly skeptical Japanese public and earmarked billions of dollars for humanitarian aid.