The Afghan Taliban called last week for its fighters to observe a three-day truce -- except against foreign forces -- to coincide with a 10-day ceasefire declared by the Afghan government for Eid al-Fitr, the holiday marking the end of the Muslim holy month of Ramadan.

Afghan journalists, students and diplomats have all reported witnessing the unusual scenes of reconciliation via Twitter over the past two days. Photos and videos purported to show handshakes and hugs in many parts of the country.

However, the mood of optimism was overshadowed by a blast Saturday in the eastern Nangarhar province, with both Taliban and civilians among at least 25 people killed and 54 wounded, according to Ataullah Khogyani, Nangarhar provincial spokesman.

The explosion occurred about 5:15 p.m. (8:45 a.m. ET) at a gathering of Taliban and Afghan civilians in the province's Rodat district, Khogyani said. The wounded were taken to hospitals for treatment, he said.

Daesh (ISIS or ISIL) claimed responsibility for the attack in a statement from Amaq News Agency, the terrorist group's media wing.

"A suicide attack struck a gathering of Afghan forces and Taliban movement in the city of Jalal Abbad in Nangarhar," the statement said, according to CNN.

Afghan President Ashraf Ghani tweeted last weekend that he was pleased the Taliban had accepted the ceasefire declaration for Eid.

"This is the first break in 23 years and we ask for your support to utilize the window for moving forward with intra-Afghan peace talks," he said.

US forces in Afghanistan also said they would respect the ceasefire with the Taliban. The truce does not include what the US calls counterterrorism efforts against groups such as al Qaeda and Daesh.