The Delhi Fire Services faced multiple challenges during the rescue operation at a coaching centre where three civil services aspirants died after the basement of the centre was flooded following rain in central Delhi, officials said on Sunday.

"It was around 7.10 pm, when we got a call from the area magistrate about the rescue operation. Though it was not a fire-related incident, we rushed five fire tenders on humanitarian grounds," DFS chief Atul Garg told PTI.

Garg further said that the major challenge was to pump out the water from the basement.

"Our pumping machines can pump the water out... But due to heavy rain, the water level on the road and the basement was equal. When we started pumping out the water, it again gushed at the same location," Garg said.

He further said the fire fighters had to wait more than half an hour to drain the water accumulated on the streets due to heavy rain.

As the water on the streets got drained naturally, fire fighters immediately launched the rescue operation by draining the water from the basement," he further said.

He also said that there was no pump in the building to pump out the water.

In the NOC from fire department, the owner of the building showed the basement as store room, but the owner violated the fire norms and was using the store room as library/classroom.

Meanwhile, the Delhi Police has arrested the owner and coordinator of the coaching centre.

Police has booked them under charges of culpable homicide among other charges, police said.

"We have registered an FIR at the Rajinder Nagar Police Station under sections 105 (culpable homicide), 106(1) (death of any person by doing any rash or negligent act not amounting to culpable homicide), 115(2) (voluntarily causing hurt), 290 (negligent conduct with respect to pulling down, repairing or constructing buildings) and 35 of the Bharatiya Nyaya Sanhita (BNS) and launched an investigation.

"So far we have arrested two people -- Abhishek Gupta and coordinator Deshpal Singh of the coaching centre," Deputy Commissioner of Police M Harsha Vardhan said.

The three civil services aspirants died on Saturday after the basement of the building, which was part of a coaching centre, was flooded following heavy rain in central Delhi's Old Rajinder Nagar area.