Afghan troops and Taliban fighters greet each other in Mihtarlam, the capital of Afghanistan's Laghman province, on Saturday, June 16, 2018, during a historic pair of unilateral cease-fires coinciding with the Eid al-Fitr holiday.

KABUL, Afghanistan — The Taliban ordered their fighters back to the trenches Sunday hours after a suicide car bombing spoiled a holiday cease-fire.

As casualty numbers continued to rise to 36 in Saturday's attack in Nangarhar province, another suicide bomber struck in Jalalabad on Sunday, killing at least 19 people. Both strikes targeted jubilant gatherings of civilians, Taliban and Afghan troops celebrating the cease-fires.

The local Islamic State affiliate claimed responsibility for Saturday's deadly attack, which experts say was likely intended to undermine the widespread optimism that had gripped the country and sow distrust at a critical juncture of peace efforts between the Taliban and the Afghan government.

“In order to prevent such events from reoccurring, the Islamic Emirate orders all its mujahedeen to remain in their trenches and areas of control and to not venture into enemy controlled areas or cities even briefly,” Taliban spokesman Zabiullah Mujahid said in a message posted online early Sunday, before the second attack that ISIS was also suspected of carrying out.

The statement blames an unspecified “enemy” for the first attack, which could refer either to the Islamic State group or the government. Mujahid said the government exploits events like the cease-fire and suggested more attacks could be imminent. He expressed concern that the Taliban could be blamed for the violence.

ISIS likely carried out the attack out of fears that Taliban reconciliation would put them in jeopardy as the next main target for government forces, said Mohammad Hasan Haqyar, a political analyst in Kabul.

“It is very clear that Daesh will attack those gatherings, which help bring peace to the country,” he said, using an Arabic acronym for ISIS. “If there is a peace deal, Deash won’t be a big problem, and the Taliban can help the government kick them out of Afghanistan.”

U.S. and Afghan forces have jointly been battling the ISIS affiliate for years, mainly in eastern Afghanistan, and have stepped up those efforts during the cease-fire. The group is not allied with the Taliban and has clashed with the insurgent group before.

The Taliban order to avoid cities came hours after Afghan President Ashraf Ghani extended the government’s unilateral cease-fire. That truce overlapped a Taliban cease-fire that began Friday on the first day of the Eid holiday and was expected to expire Sunday night.

Ghani was seeking to build on the historic cessation of hostilities, which saw images from around the country of Afghan troops and Taliban fighters praying together, greeting each other peacefully, hugging, taking selfies together and conducting impromptu parades.

“Peace is an urgent need and as it turned out that in the last 24 hours there was a consensus between the Afghan government and the Taliban on peace, it proved that we are all for peace,” Ghani said on Twitter Saturday night.

During the extended lull in offensives against the insurgents, Ghani said wounded Taliban would be provided medical care and humanitarian assistance. Prisoners would be allowed to see their families, he said, inviting the anti-government group to extend its own truce.

The Taliban spokesman rejected rumors that the insurgents would extend their cease-fire late Saturday and on Sunday the Associated Press reported that a Taliban spokesman declared the cease-fire over.

"All Mujahidin (Taliban) should continue their operations against foreign invaders and their puppets," said Zabihullah Mujahid.

Despite the order for Taliban fighters to avoid the cities, some militants were seen gathering peacefully in the Afghan capital of Kabul on Sunday morning. Such scenes, which have flooded social media since Friday, show that the Taliban want a peaceful life, said Javed Ahmad, a senior editor at Pajhwok Afghan News.

"Daesh is the real enemy of Afghans, and they can't see this big joy amongst the Afghans during a peaceful Eid,” he said. “Daesh is now in great fear after the cease-fire.”

garland.chad@stripes.com

Twitter: @chadgarland

