At least seven babies were killed and five more injured in a massive hospital fire in India.

The inferno engulfed the building and ignited flammable oxygen tanks while the infants were still inside the New Born Baby Care Hospital in Delhi on May 25.

Officials confirmed seven infants died in the blaze and the facility has been under investigation as it was found to have been running despite a two-month expired registration license to operate.

Atul Garg of the Delhi Fire Services said: 'There were twelve infants admitted to the hospital. After being saved, they were all sent to the East Delhi Advance NICU Hospital in Vivek Vihar to receive medical attention. Six of these babies were pronounced dead, while one baby passed away early in the morning.'

The fire also ripped through an adjacent residential building. Its cause is still unclear.

Police said hospital owner Naveen Kichi is facing legal charges.

Delhi Health Minister Saurabh Bharadwaj said in a statement: 'Very unfortunate incident reported. I have asked the Secretary of Health to update about the current situation. Culprits will not be spared. Strictest punishment will be ensured for those found negligent or involved in any wrongdoing.'

Meanwhile, Prime Minister Narendra Modi promised to provide monetary compensation to the affected families.

He said: ‘The fire tragedy at a hospital in Delhi is heart-rending. My thoughts are with the bereaved families in this incredibly difficult time. I pray that those injured recover at the earliest.'