Iraqi National Guard and police forces killed at least 13 insurgents Sunday after the forces were ambushed while providing security for U.S. troops conducting raids north of Baghdad.

The Iraqi forces, who were attacked by gunfire and rocket-propelled grenades, pursued the insurgents into the town of Buhriz, about 35 miles north of Baghdad. No Iraqi forces or U.S. soldiers were hurt in the hour-long clash with the insurgents, many of whom were dressed in black and wore masks, televised footage of the operation showed. It was one of the first major battles the new Iraqi forces have faced.

Iraqi security forces have become more visible since the U.S. transfer of political authority to an interim government on June 28. Iraqi and U.S. officials concede that the forces are not ready to assume full control of security operations, but they are becoming more involved in operations, including manning additional checkpoints throughout the capital in the past two days.

At a pharmacy on Sadoun Street in central Baghdad on Sunday, a pharmacist and his customers welcomed the increasing visibility of the forces.

"The situation is getting better because the Iraqis are controlling the security and the Iraqi streets," said Ali Adnan, 45, the pharmacist. "What they need is time and supplies. And I think that only Iraqis are able to control the situation because they are part of this country, and they know how to deal with the people."

But he added, "They are not ready to control everything."

"What the Iraqi forces are doing is great," said Fatima Mohammad, 38, a teacher who was buying medicine. "The U.S. forces are not like before; we see the Iraqi forces more than we see the American forces nowadays."

Mohammad also said that U.S. troops must continue to support the Iraqi police.

"We consider the new forces are newly born," she said. "Like the baby who is newly born, they need some care. If the American forces leave the country, there will be no country named Iraq."

[In a Baghdad suburb, insurgents assassinated a former government official and his son in a drive-by shooting on Sunday. Brig. Khaled Dawoud was head of the Nahyia district in southern Iraq in the government of ousted president Saddam Hussein, police Lt. Mustafa Abdullah Dulaimi told the Associated Press.

A soldier injured Saturday in a roadside bomb attack while escorting a fuel convoy near Baiji, about 125 miles northwest of Baghdad, died from his wounds, the U.S. military said. Another soldier was injured in the attack.]

Meanwhile, the Pakistani government announced Sunday that two of its citizens who disappeared Friday as they drove through Baghdad were believed kidnapped. No group has asserted responsibility for the possible abductions.

More than 70 people have been kidnapped in Iraq since April. On Saturday, the most recent victim, Raad Adnan, general director of the Iraqi-owned Al-Mansour Contracting Co., was snatched in daylight in an affluent neighborhood of Baghdad. His kidnapping came a day after the abduction of Mohamed Mamdouh Helmi Qutb, a senior Egyptian diplomat who was seized as he emerged from a mosque in the capital. Qutb was the first foreign diplomat kidnapped in postwar Iraq.

Al-Arabiya television reported that the kidnappers of seven truck drivers taken last week while working for a Kuwaiti firm have appointed a senior tribal leader to negotiate their release. A group calling itself the Holders of the Black Banners said in a statement that it had appointed Sheik Hisham Dulaymi, head of the National Group of Iraqi Tribal Leaders, to negotiate with the Kuwaiti firm and the hostages' embassies, al-Arabiya reported. The hostages are from Kenya, India and Egypt.

Elsewhere in Iraq, the U.S. military said it captured 15 people during a raid near Mandeli, northeast of Baghdad. The military said the detainees were members of a terrorist cell.

Also Sunday, Kuwaiti police said they disrupted a plot to assassinate the Iraqi prime minister, Ayad Allawi, during a visit to the country, al-Arabiya reported. No further information was available. Allawi is now in Lebanon.

The checkpoints set up Sunday in Baghdad by Iraqi and U.S. forces turned the city center into a giant parking lot of overheated vehicles. Drivers called it the worst traffic jam in recent memory.

Muhammad Hadyr, 49, who had pulled his beat-up Toyota to the side of Sadoun Street to buy a soft drink, watched the traffic creep in front of him. Hadyr, a taxi driver, said he was unable to work because of the jam.

Aqeel Kattab, 28, pulled his overheated car to the side of Sadoun Street. He stood in front of it with the hood up, pouring water over his bare feet to try to cool himself. Beads of sweat dripped into his eyes. He grimaced and wiped the sweat from his face.

"I hope this thing will not continue for tomorrow and the day after," he said. "Is this the new Iraq? It's going to be like this? We wished to have freedom and democracy. And what we gained is explosions and bad traffic. . . . Saddam was bad, but at least there was a system. Now we lost the bad guy, and we lost the system."

Special correspondents Bassam Sebti and Naseer Nouri contributed to this report.

A relative of an Iraqi policeman, mortally wounded during an attack at a checkpoint Saturday, cries during his funeral in Baghdad. Iraqi forces have expanded checkpoints in recent days.