Footage from Reuters’ partner ANI showed roads surrounding the city’s iconic Red Fort completely flooded, with broken down trucks and buses abandoned at several spots, only their windshields and roofs visible above the water.

The state government said the regulator, located near the Indraprastha metro station, was in a state of “prolonged disrepair” and collapsed around 7pm on Thursday.

“The damage caused to the regulator has resulted in Yamuna flood water flowing towards the city as its backflow,” the government said in a statement, adding that work is underway to repair the breach.

Help is also being sought from the National Disaster Response Force and the army, Delhi chief minister Arvind Kejriwal said in a Tweet.

Roads surrounding Rajghat – a memorial dedicated to Mahatma Gandhi – were inundated, with water also flowing into the memorial area itself.

The city’s ITO area, which houses several private and government offices, including the headquarters of the Delhi Police, was also flooded.

Movement on the metro rail network was affected, with the service running up to 20 minutes slower, commuters said.