Six hospital managers arrested on negligence charges are in custody for questioning after a hospital blaze killed 91 people in eastern India, authorities said Sunday.

A local court sent the six to 10-day police custody, inspector P.S. Mukhopadhyay said.

The six worked at the five-story Kolkata hospital that erupted into flames at 4 a.m.

Video of the scene showed crowds of people wearing face masks rushing patients out onto the street in stretchers.

At least 60 other people were injured, said Javed Ahmed Khan, the West Bengal Fire and Emergency Services minister.

A "majority" of the bed-ridden patients were abandoned by most of the staff on duty, he said.

The blaze started in the hospital's basement, and authorities were trying to determine its cause.

A preliminary investigation showed that the hospital had safety violations in the basement, Khan said.

In addition to using the basement as an oncology department, it was also being used to park cars and house medical supplies,, Khan said.

The hospital's license was revoked.