At least 21 people were killed when a fire ripped through a hotel in New Delhi on Wednesday, police said, in one of the deadliest blazes in the Indian capital in recent years.

Building fires are common in India due to a lack of firefighting equipment and routine disregard for safety regulations.

The fire broke out in the morning at Flourish Stay, a bed-and-breakfast in a congested neighbourhood in the south of the city, Delhi Police said in a statement.

"It is with profound sorrow that 21 persons have been declared dead in this tragic incident," the force said.