Gunmen stormed the former insurgent bastion of Samarra in northern Iraq yesterday, killing at least two elite police commandos and injuring...

BAGHDAD, Iraq — Gunmen stormed the former insurgent bastion of Samarra in northern Iraq yesterday, killing at least two elite police commandos and injuring as many as six.

Witnesses said armed men in as many as 10 civilian cars marauded through Samarra, a historic Tigris River shrine city filled with archaeological treasures. They attacked a building used by security forces with mortars and rocket-propelled-grenade launchers. The gunmen then surrounded the hospital and began shooting at it until Iraqi and U.S. reinforcements showed up, witnesses said.

Samarra was the site of a U.S.-led assault last summer meant to rid the city of insurgents. Residents said tensions had peaked in the city after a Tuesday raid on a pharmaceutical factory by security forces.

Elsewhere:

• An insurgent group with ties to al-Qaida claimed responsibility in an Internet statement for the execution of Kamal Khaled Zebari, a Kurdish security officer in the city of Mosul.

• In Baghdad, a mortar round landed in the parking lot of the Babel Hotel last night. There was no official word on casualties.

• Iraqis mourned the death of Ahmed Wael Bakri, a television director who was allegedly shot to death Tuesday by U.S. forces who mistook him for an insurgent.

• A Turkish businessman who was kidnapped in front of a Baghdad hotel in January was freed by his captors yesterday, the Turkish Foreign Ministry said. Abdulkadir Tanrikulu was taken to the Turkish Embassy in Baghdad after his release.

Information from The Associated Press and Knight Ridder Newspapers is included in this report.