JALALABAD, Afghanistan -- Militants affiliated with the Islamic State stormed a prison in eastern Afghanistan in a daylong siege that left at least 39 people dead, including the assailants, and freed nearly 400 of their fighters before security forces restored order, a government official said Monday.
The attack underscored that the Islamic State affiliate in Afghanistan is still a formidable presence, and it highlighted the challenges ahead as U.S. and NATO forces begin to withdraw following Washington's peace deal with the Taliban.
The peace accord aims to recruit the Taliban to battle the militants from the Islamic State, which U.S. officials have said is the Americans' biggest foe in Afghanistan. The Taliban and the Islamic State are staunch rivals.
At least 10 of the dead were Islamic State militants involved in the assault to free their comrades from the prison in Jalalabad, the capital of Nangarhar province, said Ajmal Omar, a provincial council member. The rest of the dead were believed to be prisoners, civilians and Afghan forces, although no official breakdown was given.
Another 50 people were wounded in the attack that began Sunday when a suicide bomber detonated his explosives-packed vehicle at the entrance to the prison complex some 70 miles east of Kabul, Omar said.
Other militants simultaneously stormed the prison and took up positions in nearby residential buildings. They fired on Afghan troops for several hours, even after the security forces retook the prison and began recapturing some of the inmates.
Of the five prisoners killed by the militants, at least three were members of the Taliban, showing the tensions between the two factions.
An AP photographer who went inside the prison, which houses about 1,500 inmates, said he saw the bodies of five of the attackers and at least four prisoners.
Omar said about 430 prisoners stayed in their cells or hid during the siege. It was unclear Monday how many prisoners remained at large.
One inmate, who gave his name as Azizullah, said he heard the powerful explosion, followed by the militants storming into the main prison block, shouting for their fighters and telling them to flee.
"The aim of this attack was to rescue all [Islamic State] members inside the prison, and unfortunately that included five or six senior [Islamic State] people," Omar said. Among the prisoners who escaped was the group's shadow governor for neighboring Kunar Province, he said.
The Islamic State affiliate in Afghanistan, known as the Islamic State in Khorasan Province, claimed responsibility for the attack. The militants have established a base in Nangarhar Province.
Afghanistan has seen a surge in violence recently, with most attacks claimed by Islamic State militants. U.S. and Afghan forces -- along with the Taliban -- have attacked Islamic State positions.
The Taliban's political spokesman, Suhail Shaheen, said his group was not involved in the prison attack.
"We have a cease-fire and are not involved in any of these attacks anywhere in the country," he said.
The Taliban had declared a three-day cease-fire starting Friday for the major Muslim holiday of Eid al-Adha. The cease-fire expired at midnight Sunday.
The U.S. reached the peace deal with the Taliban in February, but a second round of negotiations between the Taliban and the political leadership in Kabul has yet to begin.
Washington has been pushing for an early start to intra-Afghan negotiations that have repeatedly been delayed since the Taliban accord was reached.
In a tweet late Monday, Shaheen said U.S. Secretary of State Mike Pompeo held a video call with the Taliban's chief negotiator, Mullah Abdul Ghani Baradar. His Pashto language tweet said Pompeo welcomed the cease-fire.
Information for this article was contributed by Kathy Gannon of The Associated Press.
