ISIS claims responsibility for blast at Soleimani grave site in Iran that killed 84

ISIS on Thursday claimed responsibility for a deadly attack in Iran at a memorial for slain Iranian Quds Force Commander Qasem Soleimani.
The attack left dozens dead and hundreds injured, the terror monitoring group SITE reports.
CNN reports that 84 people are dead and 284 injured.
This is the deadliest attack in Iran since the Iranian revolution.