By Sinan Salaheddin The Associated PresS

BAGHDAD – About 100 masked gunmen stormed a prison near the Iranian border yesterday, cutting phone wires, freeing all the inmates and leaving behind a scene of devastation and carnage – 20 dead policemen, burned-out cars and a smoldering jail house.

At least 10 attackers were killed in the dawn assault on the Muqdadiyah lockup on the eastern fringe of the Sunni Triangle, police said. The raid showed that the mostly Sunni militants can still assemble a large force that is capable of operating in the region virtually at will – even though U.S. and Iraqi military officials said last year that the area was no longer an insurgent stronghold.

The insurgency’s strength, spiraling sectarian violence and the stalemate over forming a government in Iraq have led politicians and foreign policy experts to say Iraq is on the brink or perhaps in the midst of civil war.

In all, 33 prisoners were freed, including 18 insurgents who were detained Sunday during raids by security forces in the nearby villages of Sansal and Arab, police said. It was the capture of those insurgents that apparently prompted yesterday’s attack. The other 15 inmates were a mix of suspected insurgents and common criminals.

In an Internet posting last night, the military wing of the Mujaheddin Shura Council, a militant Sunni Muslim insurgent group, purportedly claimed it carried out the operation. The posting said the group killed “40 policemen, liberated 33 prisoners and captured weapons.”

The claim was posted on the Iraqi News Web site. Neither the higher casualty toll among policemen nor the captured weapons could be independently verified.

The cutting of the telephone lines made it impossible for jailers or security men – who apparently did not have cell phones – to call other police for backup. Residents of the town informed authorities of the situation after hearing the firing.