The boys fled at around 5.45 am in a Maruti 800 car, which did not have a number plate, waiting outside the home, sources said.

The Delhi Home Guard officials, responsible for security at the home, told senior officials that they had taken the boys out “just for a walk.”

The runaway inmates—Pradip Sehravat (17), Rakesh Pal (18), Parvez Mabi (19), Jai Kant (18) and Irshad Kamaluddin (18)—have attempt to murder and murder charges registered against them, officials at the observation home said.

Minister of Health and Social Welfare Dr Yoganand Shastri has ordered that a Joint Secretary-level inquiry report be submitted to him in three days, officials said.

An inmate Newsline spoke to said the escape was “pre-planned”. The boy said the five accused had their own mobile phones inside the institution, which is illegal.

“Pradip was the one who called the car. The five of them then went out of the institution, escorted by an officer. A black Maruti car was parked right outside the front gate,” the boy said.

The guards at the gate of the complex are supposed to take down registration numbers of cars entering the home, but no entry was made. Officials said the security guard responsible will be questioned.

The institution has round-the-clock security. Just three months back, the Delhi Home Guards was given charge of the security.

There are three shifts, with 12 officials standing on guard in each shift. “All the 12 Home Guards officials at the home as well as the seven home karamcharis have been issued notices as to why they should not be held responsible for the incident,” said a government official.

Officials said the five boys were earlier lodged in Tihar Jail but transferred to the observation home after a court-ordered inquiry found they were below 18 years of age. Bone marrow tests were done to ascertain their age, officials said.