In one of the deadliest single attacks in months, a suicide bomber from ISIS detonated in a crowd of protesters on Tuesday, killing at least 68 civilians in Nangarhar Province, and wounding another 165.

Local hospitals in the Momand Dara District, where the attack took place, were quickly overwhelmed by the sheer number of casualties, and were not meant to handle so many wounded all at once. Two separate bombers took place in the same area earlier in the day, though it’s unclear if they are related.

The protest was organized against a local police commander, and officials have said they doubt that the topic was related to the attack. Rather, it appears to have simply been an opportunity to hit a large number of people in public.

With the nationwide parliamentary election in October, this could just be the first of many such attacks in Afghanistan. Public campaign rallies will be increasingly common in the weeks to come, and those public gatherings are likely to also be targets for militants looking to inflict heavy casualties, and underscore the nation’s poor security.