Rescue teams pulled bodies from the wreckage of the Omid Addiction Treatment Hospital in Kabul after a Pakistani air strike late Monday.
The attack occurred at 21:00 local time as patients finished dinner for Ramadan. The Taliban government says approximately 400 people may have been killed, though the figure remains unconfirmed.
Mohammad Shafee, a survivor, said he was serving food when the blast hit. Only five of his group made it out alive.
Doctor Maiwand Hoshmand confirmed patients were in prayer when jets struck three areas of the facility. Security guard Omid Stanikzai reported military units fired first, prompting the jet to drop bombs.
Pakistan denies intentionally targeting the center, stating it struck military installations and terrorist infrastructure. The UN reports at least six health facilities in Afghanistan have been impacted since February.
The Omid centre, formerly Camp Phoenix under US-NATO use, housed up to 5,000 addicts-double its capacity-after Taliban crackdowns on drug use.
Families gathered at the site searching for missing loved ones. At least 100 bodies have been sent to forensic services, many too disfigured for immediate identification.