KABUL — At least 29 people were killed after Daesh (the so-called IS) militants attacked a prison believed to be holding hundreds of Daesh members in the eastern Afghan city of Jalalabad, 112 km east of Kabul.

The attack, claimed by Daesh began on Sunday evening when car bombs were detonated at the prison's entrance by gunmen.

The attack highlighted the challenges ahead for Afghanistan, as the United States and NATO forces begin to withdraw after the US struck a peace deal with the Taliban.

Eight of the attackers were killed in a battle lasting almost 20 hours, a Nangarhar province spokesman said.

The dead included civilians, prisoners, guards and Afghan security forces, the spokesman added. A number of prisoners remain missing.

Even as Afghan troops seized the prison, Daesh militants continued to fire on Afghan security forces from a nearby neighborhood.

There were 1,793 inmates in the prison at the time of the attack — most of them Taliban and Daesh fighters, a security source told the AFP news agency. It was not immediately clear if the attack had been staged to free specific prisoners from the complex.

Sunday's attack came a day after Afghanistan's intelligence agency announced that the country had killed a top Daesh commander, Assadullah Orakzai, near Jalalabad. Orakzai had allegedly been involved in several deadly attacks against Afghan security forces.

The Taliban’s political spokesman, Suhail Shaheen, told the Associated Press that his group was not involved in the attack.

“We have a ceasefire and are not involved in any of these attacks anywhere in the country,” Shaheen said.

The Taliban declared a three-day ceasefire starting on Friday for the Eid al-Adha holiday. The ceasefire expired on Monday though it was not immediately clear if it would be extended. — Agencies