JALALABAD, Afghanistan — Extremists in eastern Afghanistan bombed a peaceful protest on Tuesday, killing at least 68 people, officials said, the deadliest in a series of attacks in Nangarhar Province over the day.

The bombings, which also struck three schools, followed a pattern of recent attacks by the Islamic State in Afghanistan, which has publicly vowed to target educational institutions and which staged a seven-hour assault on a school for midwives in the provincial capital, Jalalabad, in July.

The attack on protesters gathered in Momand Dara District, in a rural part of Nangarhar, also left at least 165 wounded, according to Attaullah Khogyani, the spokesman for the governor of Nangarhar.