Led by BJP leader Harsh Vardhan, the protesters held up placards demanding the Aam Aadmi Party minister's ouster and raised slogans against him.
"It is our right to demand the sacking of the law minister who has been most unlawful," Harsh Vardhan told the media.
Kejriwal came out of his office and had a brief chat with Harsh Vardhan. The Bharatiya Janata Party said the protest would continue till Bharti was sacked.
The protests follow what critics say was a vigilante foray by Bharti into a south Delhi neighbourhood at night following complaints from residents about a drug-and-prostitution ring allegedly involving some Africans.
The campaign led to a stand-off with Delhi Police, eventually forcing Kejriwal to stage a controversial protest against the police in the city. A lawyer by training, Bharti has denied any wrongdoing.