Kurdish militiamen battled Islamic militants believed to be linked to Al Qaeda in northern Iraq early Wednesday, and as many as 30 militiamen were killed or wounded, Kurdish military officials said.

Militants from the Ansar al-Islam seized two hilltop positions of the Patriotic Union of Kurdistan (PUK) near the city of Halabja, said Sheik Jaffar Mustafa of the PUK, the Kurdish militia that is the de facto authority in the area.

Mustafa said he believed his force had suffered as many as 30 casualties, but he could not give an exact figure since some of his forces were on leave and his side had been unable to retrieve bodies from the battlefield.

He also said he did not know how many among the casualties were dead, nor how many Islamic militants had been killed or wounded. Some of the PUK fighters died while sleeping since the Ansar al-Islami launched its attack before daybreak.

The PUK is the main authority in the Halabja area. The milita and its rival, the Kurdistan Democratic Party, control the Kurdish autonomous zone in Iraq.

Smoke could be seen rising from near the two hills at the base of the Suren Mountains along the Iraq-Iran border. The guerrillas from Ansar al-Islam fired heavy artillery as they charged the Kurdish positions, Mustafa said.

While some of the Ansar al-Islam forces are Kurds, Mustafa said they also include Arabs who trained in Afghanistan and are believed to have ties to the Al Qaeda terrorist movement of Usama bin Laden.

The PUK rushed in reinforcements from its special forces as ambulances took wounded fighters to Halabja, six miles away. Officials at the Halabja hospital said they treated six victims of gunshots.

Mustafa said the Islamic militant fighters had succeeded because the PUK had sent some of its forces home on leave for the Islamic holiday of Eid el-Fitr, which begins Thursday and marks the end of the Muslim fasting month of Ramadan.

"They took advantage of the situation," he said. "Everywhere in the Muslim world people usually stop fighting for Ramadan."

Halabja, the city near the battle, was the scene of a notorious poison gas attack by the Iraqi army on Kurds near the end of the Iran-Iraq war in March 1988.

An estimated 5,000 people were killed in the attack, which U.S. officials have often cited as an example of Iraqi President Saddam Hussein using lethal weapons on his own people.

Battles between the PUK and Ansar al-Islam intensified in November 2001 in the Kurdish autonomous region in northern Iraq, Mustafa said.

Kurds arose against Saddam after the 1990-91 Gulf war. The revolt was put down, but an autonomous Kurdish region was established, protected by overflights by U.S. and British aircraft.

The PUK controls the eastern part of the autonomous zone, while the western sector is controlled by the Kurdistan Democratic Party.

The Ansar al-Islam militia held Halabja from 1998 to 2000, but was driven out by the PUK fighters.

Mustafa said the Islamic militants had repeatedly attacked the PUK in the last few months, most recently trying to seize one of his militia's checkpoints in November.

"Each time they've attacked they've been defeated," he said. "This time they took a chance and got lucky."

He said his forces would launch a counterattack, probably on Thursday, but that it would be a difficult battle.

"The Ansar is in a good, high place," he said. "They have dynamite and they often booby-trap the areas. It's not an easy job to retake these positions."