Members of a new security force under government control guarded main intersections and expanded patrols Tuesday under an accord by northern warlords to stabilize the potentially volatile city.

The force, which is expected to expand to 600 members, is part of an agreement under which the region's main warlords are to withdraw their forces from Mazar-e-Sharif and demobilize all but a few of the fighters.

A pullout by warlords from Mazar-e-Sharif would be an important step in Afghanistan's efforts to restore stability after 23 years of war. Factional fighting continues to break out two months after the fall of the Taliban and even when there is no shooting tensions are high among factions jockeying for control.

Talks continued Tuesday on resolving tensions in the eastern town of Gardez, where two days of fighting last week killed at least 61 people.

Ending such conflicts is key to interim Prime Minister Hamid Karzai's attempts to solidify its authority. Afghanistan has no national army and an international peacekeeping force's activities are limited to Kabul, the capital.

The Mazar-e-Sharif withdrawal was expected to have begun Tuesday but was postponed until the return from abroad of Gen. Rashid Dostum, leader of one of the main militias and the country's deputy defense minister. None of Dostum's aides would speak for the record during his absence but said his faction supports the agreement.

Militiamen with AK-47s still moved through the city on foot and riding in trucks loaded with rocket-propelled grenades.

The new security personnel wore identical red insignia, in contrast to the mismatched military garb and civilian clothes typically worn by militia members.

The security force leader picked by the interim government, Gen. Mohammad Isa Eftakhouri, said he hopes to have the militias out of the city within 10 days, after which the difficult task of disarming civilian gunmen will begin.

Nearly every home in northern Afghanistan has some weapons and Eftakhouri said getting rid of them is critical.

"We only want security personnel to have guns, not ordinary people. We will take the guns even if people resist," Eftakhouri said.

The security force is to include men from each of the region's three main militias — Dostum's, his rival Atta Mohammad's and a third faction under Mohammed Mohaqqeq.

Whether that participation will ensure that the militia commanders demobilize and disarm their tens of thousands of fighters is "our major worry," said Eftakhouri.

Karzai's government has appealed for peacekeepers to be expanded to cities other than Kabul — so far without success.

In Washington, the chairman of the Senate Foreign Relations Committee urged President Bush to allow U.S. troops to participate in the peacekeeping force.

"Like it or not, our leadership role must include soldiers on the ground. If others step forward, fine, but whatever it takes, we should do it," said Sen. Joseph Biden, who visited Kabul in January.

Bush has ruled out participation by American troops in the British-led force, although Washington says its troops will stay in Afghanistan hunting Al Qaeda and Taliban fugitives.

In Kabul, the commander of the international peacekeeping force and Afghanistan's interior minister told a joint news conference that security there is improving despite pockets of lawlessness.

"There are of course difficulties, and there remain difficulties," British Gen. John McColl said Monday.

But he pointed to growing commercial vitality in the city and increased traffic in and out of Kabul's international airport as signs that stability was taking hold.

Interior Minister Younis Qanooni, appearing at a news conference with McColl, spoke of Afghanistan's wish to become "self-sufficient" in security matters. He said the country hoped to have a 70,000-member national police force trained within the year.

Also Tuesday, Afghanistan's new national flag was raised at the presidential palace in a ceremony attended by Karzai.

The red-green-and-black flag is similar to those that flown during the reign of exiled King Zaher Shah and variations used sporadically since then, but with some changes. It has a small white-lettered inscription and horizontal stripes instead of vertical ones, and a band of black replacing the previous white.

"We hope this symbolizes a great opportunity for us, that our country will progress like other nations," Karzai said.

In other developments:

—Defense Secretary Donald H. Rumsfeld said Monday that American forces have returned to investigate claims they killed the wrong people in a raid two weeks ago on a school building. Fifteen or 16 people died in the raid, which the Pentagon said targeted Taliban and Al Qaeda holdouts.

—The Bush administration's proposed 2003 Pentagon budget includes $27 billion for fighting terrorism. The Pentagon says it has spent about $7 billion so far on its campaign in Afghanistan, which began Oct. 7.