American soldiers shut down the biggest Kurdish guerrilla checkpoint in occupied Iraq Thursday, in a sign of growing impatience with Kurdish leaders for not cooperating with moving refugees down from the mountains.

The allies also said they had received assurances from a representative of Saddam Hussein that Iraqi troops would avoid shooting incidents like the firing of anti-aircraft guns at a U.S. Navy plane early Wednesday.Iraqi and allied troops continued their standoff at Dohuk, the main Kurdish city in northern Iraq. The standoff has prevented expansion of the "safe haven" zone created to encourage thousands of refugees to return to their homeland from spartan camps along the Turkish border.

Backed by three helicopter gunships, U.S. Army military police in a dozen Humvees drove to the guerrilla checkpoint just outside Zakho Thursday morning and ordered it dismantled. The Kurdish fighters left.

"The rules are no armed Iraqis and no armed Kurds and no Iraqi checkpoints and no Kurdish checkpoints," said Col. Lucious Delk, commander of the MPs.

Allied officers have criticized the checkpoints for interfering with the return of Kurdish refugees. They say the roadblocks are a cover for Kurdish guerrillas to extort money or steal things from refugees.