A nine-year-old boy was feared drowned in the Yamuna river stretch in south-east Delhi’s Shaheen Bagh area, police said on Saturday.
Efforts are under way to trace the boy, they added.
The incident took place on Friday evening when Mohammad Ahsan and his friend Rajkumar were swimming in the river, a senior police officer said.
As Ahsan suddenly slipped into deep waters, two persons -- Rohit and Alam -- who were on the bank jumped into the river but failed to rescue him, the officer added.
On being informed, police rushed to the spot and started a search operation, they said.
Fire personnel and four divers have been deployed to trace the boy, the police added.
The statements of Ahsan's father, Rajkumar, Rohit and Alam have been recorded, the police said.
The river water level, which has been hovering around the danger mark of 205.33 metres for the last few days, dropped below the threshold again on Saturday morning.
The Central Water Commission's (CWC) data showed the water level dropped to 205.16 metres at 4 pm on Saturday. It may drop further before the impact of rain in upper catchment areas becomes clear.
At 208.66 metres on July 13, the Yamuna surpassed its previous record of 207.49 metres set in September 1978 by a significant margin.