"The accused, aged around 40 years, forcibly took the 12-year-old girl to the park, sexually assaulted her and fled," Investigating Officer in the case, Sub-Inspector Kuldeep said.
Indian Youth Congress president Srinivas BV, who led the protesters, said the Uttar Pradesh chief minister should immediately resign for the "shameful" behaviour of the state police with Priyanka Gandhi.
The Delhi Police on Tuesday said protesting farmers violated the conditions pre-agreed for their tractor parade and indulge in violence and vandalism, leaving 83 of its personnel injured.
However, the faces of the persons occupying the vehicles or their registration numbers were not clearly visible.
Some residents of Nani Daman area alerted the police about suspicious movements of six persons in military uniform on Wednesday, thinking they could be terrorists.
Police said the border has not been sealed but they are checking all vehicles entering the national capital.
The workers, who were protesting reportedly against the farm bills brought by the Centre, which recently received the assent of President Ram Nath Kovind, had brought the tractor to the site on a truck.
Some taxi and cab unions, including those associated with app-based aggregators, have decided to join the strike called by farmers organisations demanding repeal of three new farm sector laws.
The ministry of home affairs in its advisory on December 28 had advised states and Union Territories that they can impose local restrictions, including night curfew, based on their assessment of the situation to contain the spread of COVID-19.
The child, whose parents work as labourers in a factory, was beaten and brutalised with a sharp object. She is critical and on oxygen support, said a senior doctor at the All India Institute of Medical Sciences where she is admitted.
Taking on the Adityanath government over handling of protests against the amended Citizenship Act, Congress leader Priyanka Gandhi Vadra on Sunday said it has "crossed all limits of inhumanity" and claimed party worker Sadaf Zafar was arrested on "baseless" charges.
Congress accuses Centre of 'protecting' state BJP chief's son.