Al Qaeda in Iraq (search) claimed responsibility Wednesday for killing two Algerian diplomats who were kidnapped in Baghdad last week — the second slaying of Arab envoys in Iraq this month.

Algerian state radio said Ali Belaroussi (search) and Azzedine Belkadi (search) had been killed, although the announcement from President Abdelaziz Bouteflika did not provide the source of the information.

Belaroussi, 62, and Belkadi, 47, were kidnapped at gunpoint July 2 home addresses.

Meanwhile, progress on Iraq's new constitution ran into another snag as Iraqi Kurds threaten not to back down from demands for a federal state despite problems this may create in meeting an Aug. 15 deadline that U.S. officials are pushing.

Massoud Barzani, head of the Kurdistan Democratic Party (search), also said Kurds would never dissolve their militias and repeated demands for the return of ethnic Kurds to the oil-rich Kirkuk area from which tens of thousands of them were expelled under Saddam Hussein.

Barzani's comments, broadcast by Al-Arabiya television, indicated the Kurds are standing firm on longtime demands at a time when the United States is urging all sides to compromise in order to finish the new constitution by the Aug. 15 deadline.

His remarks were broadcast as Defense Secretary Donald H. Rumsfeld (search) arrived in Baghdad to urge the Iraqis not to miss the deadline for completing the draft of the constitution. The Defense Department wields considerable influence among the Kurds, who worked closely with the Americans in preparations for the 2003 invasion that toppled Saddam.

"It's time for a compromise. That's what politics are about and people are simply going to have to recognize that (in) any constitutional drafting process, compromise is necessary. It's important. It's understandable. It's the way democratic systems work," Rumsfeld said.

At a joint news conference with Rumsfeld, Prime Minister Ibrahim al-Jaafari said the time has arrived to plan a coordinated transition from American to Iraqi military control throughout the country.

Asked how soon a U.S. withdrawal should happen, he said no exact timetable had been set. "But we confirm and we desire speed in that regard," he said, speaking through a translator.

Speaking earlier with U.S. reporters traveling with Rumsfeld, Gen. George Casey, the top American commander in Iraq, said he believed a U.S. troop withdrawal could begin by spring 2006 if progress continues on the political front and if the insurgency does not expand.

In ongoing violence, a bomb exploded Wednesday near a U.S. Army patrol in central Iraq, killing one soldier and wounding five others, the U.S. command said.

The attack occurred in Salaheddin province in the Sunni Triangle north of Baghdad, a center of the anti-American insurgency. The soldiers were assigned to Task Force Liberty based in Tikrit but their names were not immediately released, the U.S. command said.

Preliminary drafts of the Iraq's constitution call for disbanding all militias associated with Iraqi parties since the days when they were fighting Saddam. The Kurds have long maintained that their peshmerga fighters are not a militia but rather the security force of their autonomous Kurdish region in the north.

However, it is unlikely that the Shiites and others would accept an end to their own militias if the Kurds are allowed to keep their peshmerga fighters.

"The peshmergas will stay and there is no force that will be able to cancel them," Barzani said. He said the issue of Kirkuk must be resolved according to a formula the Kurds accepted before U.S. authorities restored Iraqi sovereignty — which states that all Iraqis, including Kurds, who were displaced under Saddam Hussein's regime have the right to return to their homes and receive compensation.

That could anger many Sunni Arabs, who were moved into the Kirkuk area after the Kurds were expelled, and also Turkomen, who consider Kirkuk as their homeland too. Turkey has given strong support to the demands of their Iraqi ethnic kinsmen.

Many Sunni Arabs are also suspicious of federalism, fearing it would lead to the breakup of the nation. Federalism also raises questions about the distribution of oil revenues, including how much should go to the central government and how much to any regional federated districts.

In other developments in Iraq:

— A senior Baghdad International Airport official was abducted Wednesday by gunmen, police said. Mahir Yassin, director of the communication department at Baghdad airport, was kidnapped from Baghdad's western Mansour neighborhood on his way to work by assailants in two cars.

— Mortar attacks on Baghdad's main bus station Wednesday killed at least two and injured 20 others, said Dr. Muhannad Jawad of Yarmouk Hospital. Most of the victims are believed to be Iraqi civilians.

— Gunmen opened fire Wednesday on a car carrying three employees of the Ministry of Trade, killing one man and wounding two women, Baghdad police said.

— In Tikrit, Iraqi police said gunmen fired on a truck carrying Iraqis working at a U.S. garrison near Oja, birthplace of Saddam Hussei, killing one and injuring seven.

— Seven Iraqi soldiers were shot and killed as they were guarding a water plant north of Baghdad, the Defense Ministry said Wednesday. About 20 assailants armed with hand grenades and light weapons drove up in four cars and opened fire Tuesday in Tarmiyah, 30 miles north of Baghdad.

— Two homicide attackers who apparently targeted the Iraqi military blew themselves up in quick succession on Wednesday outside a hospital in northern Baghdad, killing two soldiers and wounding eight, police Maj. Suleiman Abdul-Wahed said.