Maliwal who is on the strike demanding strict and swift punishment to the convicts in such cases, refused to listen to police’s request and continued with her protest.
Police had asked her to vacate the premises citing a standing order that prohibits protests at the venue after 5 pm.
Hundreds of women joined Maliwal in her protest against the gangrape and murder of a young veterinarian in Hyderabad and the brutal rape of a six-year-old girl in Rajasthan.
Maliwal said she has written to Prime Minister Narendra Modi, demanding that rapists be hanged within six months of their conviction.
"My demand to PM is that we want capital punishment for the rapists of minor and major victims. The accused in the Hyderabad case must be hanged. Last year, I sat on protest and within 10 days, the government made a law that the rapists of minors will get capital punishment within six months, but this did not happen.
"I want the PM to implement the law now. I am demanding strict and swift punishment," she said, adding that the process to decide on mercy petitions should be time-bound.
The DCW chief said there is a shortage of 66,000 police officers and 45 fast-track courts in the capital Delhi. "We need to enhance the infrastructure for a better implementation of the law."
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She claimed she did not receive "a single reply" from the prime minister to the "hundreds of letter" she wrote to him as chief of the Delhi Commission for Women.
"He should encourage us that we are with you. We are not against the government."
She said the Delhi police denied her permission to hold the protest at Jantar Mantar, but police said they have not rejected her demand.
Police said a letter was sent to DCW seeking details about the nature of the protest, mode of transport, microphone arrangements and the number of protesters expected there, with a copy of an undertaking to be filled according to Supreme Court guidelines.
Those details are awaited, they said.
But Maliwal said, "The Delhi police is also not supporting us. We do not have any tent here and it will be difficult for us to spend the night. They are threatening us that they will throw the protestors out by 5 in the evening."
"I want to tell Delhi police that we are protesting so that your force will get 66,000 new officers. I am not a criminal, I want your (Delhi police) support and I appeal to the countrymen that they should come out in large number and support us," Maliwal added.
(Inputs from PTI)