Videos from the crash scene showed plumes of thick, black smoke rising from behind the buildings where the helicopter went down.
The source said those killed included 19 soldiers, one army major and two colonels.
The soldiers received a ceremonial funeral with their coffins draped in Pakistani flags and carried by members of the artillery unit stationed in Kashmir.
Pakistan’s military said on Wednesday that the Mi-17 helicopter crashed due to a technical fault and all those on board were killed.
An inquiry has been ordered into the exact technical cause of the accident, it added.
The crash took place at a time when strict security restrictions have been imposed on Kashmir following clashes between supporters of a recently banned alliance of civil society groups and security forces that killed at least 11 people on Sunday.
(Reporting by Saad Sayeed, Writing by Hritam Mukherjee and Saad Sayeed; Editing by YP Rajesh, Alexandra Hudson)

Pakistani Army soldiers carry a coffin during the funeral of victims after a Pakistan Army Aviation Mi-17 helicopter crash near Muzaffarabad, Pakistan-administered Kashmir, Pakistan, 11 June 2026. The Pakistan Army Aviation Mi-17 helicopter crashed during take-off after reportedly developing a technical fault. All personnel on board were killed in the accident. Rescue and recovery teams were deployed to the crash site, while military authorities ordered an inquiry to determine the exact cause of the crash. EPA/AMIRUDDIN MUGHAL