The plan has engendered intense criticism by Shiite leaders involved in negotiations with American and British officials who have met privately with the heavily armed political groups that have moved into the power vacuum here.

"Maybe we didn't fight with the coalition, but we didn't fight against them," said Adel Abdul Mahdi, an official of the largest Shiite group, which is headed by Ayatollah Muhammad Bakr al-Hakim. "We want conditions where all militias are dissolved and we will not accept that other militias will be allowed to stay there with their weapons while we will not be there with ours."

Under the draft order, obtained by The New York Times, "militias that assisted coalition forces who remain under the supervision of coalition forces" will be authorized "to possess automatic or heavy weapons." 

In a press conference today, Lt. Gen. David D. McKiernan, commander of allied land forces in Iraq, said that under the directive there "will be no militias inside of Iraq," but then added that the Kurdish forces, known as pesh merga, "are a different story."

"The pesh mergas fought with coalition forces and we look to leave them with some of their forces north of the green line," he said, referring to the line that once divided the Kurds into two self-governing enclaves in the north from the parts of Iraq under the control of Saddam Hussein.

The directive would allow ordinary Iraqis to retain some arms, including pistols, rifles and shotguns, but would ban AK-47 automatic assault rifles, machine guns, mortars, grenades and heavier weapons such as artillery, antitank weapons and armored vehicles.

The top civilian administrator in Iraq, L. Paul Bremer III, issued a separate directive today formally dissolving Iraq's armed forces as they existed under Mr. Hussein. Mr. Bremer abolished the Ministry of Defense, the Ministry of Information, the Republican Guard and other security institutions "which constituted and supported the most repressive activities of Saddam Hussein's regime." 

A spokesman for Mr. Bremer said in a statement that the coalition planned to create "in the near future, a New Iraqi Corps." 

"Under civilian control, that Corps will be professional, nonpolitical, militarily effective, and representative of all Iraqis," the statement said.

Besides the armed Shiite groups, the main militia in Iraq are the Kurds and the Free Iraqi Forces of the Iraqi National Congress under Ahmad Chalabi.

General McKiernan said today that Mr. Chalabi's militia was being "demilitarized."

When Mr. Chalabi's militia first surfaced in Iraq last month, it received training from under the supervision of an American Special Forces officer.

On Thursday night, armed fighters from the Iraqi National Congress engaged in a running gun battle with unknown foes during what was described as a search by Mr. Chalabi's forces for senior Baath Party members in a Baghdad suburb. 

After the firefight, American troops raided Mr. Chalabi's headquarters at Baghdad's Hunting Club, arrested 35 of his militiamen and seized their weapons. They were released, Mr. Chalabi's group said in a statement, after an American military officer assigned as a liaison to the group intervened.

Kurdish and Shiite Muslim leaders confirmed in interviews this week that senior military commanders, including Lt. Gen. John Abizaid, the deputy commander of American forces in the region, and General McKiernan had briefed them on the disarmament directive and issued some pointed warnings that they would be disarmed by force if they did not comply.

In one meeting this week, General Abizaid implied that that one militia, the Badr Brigade, was controlled by a "foreign government," meaning Iran, according to several Iraqis who attended that meeting. The Badr Brigade is under the command of Ayatollah Hakim, who arrived in Iraq from exile in Iran earlier this month.

The directive comes at a time when the strength of each group's militia has become a symbol of power and potential leverage for the Iraqis seeking to establish a provisional government. Some of these Iraqis are complaining that American and British leaders are pursuing a policy that will alienate the Shiites, who make up 60 percent of Iraq's roughly 24 million people. 

American civilian and military leaders insist they are trying to bring order out of chaos here and to begin a process of disarmament that will pave the way for building a professional Iraqi military force.

The muscular posture against the Iranian-backed militia of Ayatollah Hakim is in accordance with recent sharp pronouncements by the Bush administration, which has accused Iran of giving support to leaders of Al Qaeda.

Mr. Abdul-Mahdi of Ayatollah Hakim's Supreme Council for the Islamic Revolution in Iraq said the Badr Brigade had more than 10,000 soldiers under arms in Iraq. American officials are deeply suspicious of this force because it was financed and trained in Iran, where Ayatollah Hakim maintained his base of operations during Mr. Hussein's rule.

The conflict over arms policy in Iraq was evident this week when allied forces clashed with militiamen whose ranks have been growing in strength and weaponry since the end of the war.

In Baquba last Sunday, American forces ejected a Shiite militia force from a municipal building the group had seized about 50 miles northeast of Baghdad. American troops killed one militiaman and arrested dozens of others, a military official in the city said today.

Kurdish forces also have had their arms confiscated by coalition troops in numerous incidents. But Jalal Talabani, the Kurdish leader whose forces have cooperated closely with the Americans in northern Iraq, said in an interview today that he had been assured that Kurdish forces would retain their heavy weapons, including tanks, armored personnel carriers, antiaircraft weapons, artillery and heavy machine guns. He estimated the size of those forces to be about 100,000, but other estimates are around 70,000.

Saying he was loath to criticize his "friends and allies" in Washington, Mr. Talabani said that if the Americans "want to reduce the influence of others" like Iran, on the Shiites, "they must request that Hakim and his group" be integrated into the new Iraqi armed forces. 

It was not clear what the reaction of neighboring Turkey to the new directive would be. Turkey, a NATO ally, angered the Bush administration by refusing to allow American troops to move through Turkey to open a full-fledged northern front in the Iraq war. The Turks are suspicious of Kurdish nationalism in Iraq, fearing that will stimulate separatism among the sizable Kurdish minority in Turkey.

Mr. Abdul-Mahdi challenged American suggestions that Kurdish forces were more trustworthy than other militia forces.

"All Shiites are accused of being Iranians," he said. "I defy any person to find any Iranians" in the Badr Brigade, he added. He said that Kurdish militiamen had a long history of cooperating with Iran, and asserted that the Badr Brigade suffered as much or more from Mr. Hussein's repression as the Kurds. 

"Most of the mass graves they are finding are full of Badr Brigades and their families," he said.

The new directive will be signed by Mr. Bremer and General McKiernan, according to the draft, which is dated May 18 and has been the basis for this week's private negotiations with Iraqi opposition figures.

Under the draft policy, which is expected to be issued before June 1, "small arms may be possessed in homes." Such arms include rifles, shotguns, and pistols, but no automatic weapons. In order to carry such weapons outside homes, individuals or groups must have a "weapons authorization card."

The directive also says that public arms markets will be prohibited.