New Delhi, Aug 21 - At least 20 flights were delayed and 10 diverted in the national capital Friday evening following gale and torrential rains that also flooded and damaged a portion of the new domestic terminal building.

'Heavy downpour resulted in some water entering into the domestic terminal building 1D. The maintenance team is working on war footing to clear the water and restore the displaced sheets,' the Delhi International Airport Ltd (DIAL), the developer of the IGI airport, said in a statement.

An airport official said no one was injured when a portion of the new terminal building roof collapsed.

The government has taken a serious note of the terminal flooding and a report has been sought from DIAL on the flooding and damage of the terminal, a civil aviation ministry spokesperson said.