The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group has claimed responsibility for a suicide bombing that killed at least 36 people and wounded 65 others in the eastern Afghan province of Nangarhar.

The group’s Amaq website said the attack on Saturday targeted “a gathering of Afghan forces” in Nangarhar, but gave no details.

According to Attaullah Khogyani, the provincial governor’s spokesman, the attack happened in Rodat district, some 25km from Jalalabad.

Civilians, security forces and Taliban members were among the casualties as people celebrated the second day of Eid al-Fitr, marking the end of the Muslim holy month of Ramadan.

Speaking from Afghanistan’s capital, Kabul, Al Jazeera’s Jennifer Glasse described the bombing as a “very devastating blow” for the “unprecedented gathering of the Taliban and Afghan security forces in Jalalabad”.

Extension of government ceasefire

The attack came as Afghan President Ashraf Ghani announced the government’s extension of a ceasefire with the Taliban, without giving a timeframe.

In a televised address to the nation, Ghani called for the Taliban to also extend the truce, which is due to expire on Sunday after both sides agreed to halt hostilities for Eid.

Ghani also said that in the spirit of Eid and the ceasefire, the attorney general’s office had released 46 Taliban prisoners.

The Taliban had announced a ceasefire for the first three days of Eid, which started on Friday, promising not to attack Afghan security forces for the first time since the 2001 US invasion.

That came after Ghani said that security forces would temporarily cease operations against the Taliban for eight days, starting last Tuesday – though he warned that operations against other fighters, including the Islamic State of Iraq and the Levant group, would continue.

Governors in Helmand, Kandahar and Zabul said both sides had adhered to the ceasefire.

In his speech, Ghani also touched upon the subject of regional influences and international forces in Afghanistan.

“The Afghan government is ready to discuss the roles of neighbouring countries and the presence of international forces, their roles and the future destiny of them,” he said.

Mike Pompeo, the US secretary of state, welcomed Ghani’s remarks.

“We support President Ghani’s offer to extend the ceasefire and begin peace talks,” Pompeo said in a statement.

“As President Ghani emphasised in his statement to the Afghan people, peace talks by necessity would include a discussion of the role of international actors and forces. The United States is prepared to support, facilitate, and participate in these discussions.”

NATO forces also expressed their support for an extension to the ceasefire.

“This is a unique opportunity for the Taliban to show they want the peaceful future that the Afghan people demand and deserve,” NATO Secretary-General Jens Stoltenberg said.

“There seems to be some momentum for peace,” Al Jazeera’s Glasse said.

“The government’s gamble to issue a unilateral ceasefire paid off with this Taliban ceasefire, and now everyone is going to wait and see what the Taliban is going to do.”

Omar Samad, a former adviser to the chief executive of Afghanistan, told Al Jazeera that the suicide bombing was a reminder to everyone in the country, including the Taliban, of the “existentialist threat on our doorstep”.

What we saw today is a reminder that ISK (the Islamic State branch in Afghanistan) is a potent threat, that something needs to be done about it,” Samad said, speaking from Washington DC.

“Maybe the Taliban and the Afghan government can come to terms on how to deal with the Islamic State,” he added.

“That could be a historic point for maybe a dialogue between the two sides. If that happens then I think that Afghanistan has better days ahead. ”