A 30-year-old man, suffering from mental illness, was detained on Monday for allegedly trespassing into Delhi Commission for Women (DCW) chief's residence and vandalising her cars, police said.

Swati Maliwal said a man forcibly entered her residence and vandalised her as well as her mother's car while she was out of town. She also wrote to Delhi Police commissioner Sanjay Arora seeking urgent action on the matter.

Police said the attacker, identified as Sachin, a resident of Nathupura, was found to be suffering from mental illness. He has been sent to the Institute of Human Behaviour and Allied Sciences (IHBAS).

A case has been registered under the section of trespassing and damaging private property, they said.

"The windshields of the cars were broken with some sharp object and the roof and other parts of the cars were damaged as well. The attacker also tried to break into the house too. Some labourers who were around, informed that the man was carrying a knife as well," Maliwal said.

In her letter to Arora, the DCW chief has described this incident as deeply disturbing.

She said in the past seven years, during her tenure as the DCW chief, she has done tremendous work on women's rights and this attack could possibly be an attempt to intimidate her.

"From exposing prostitution in spas, acting against illegal liquor and drugs, taking action against criminals in online and offline complaints as well as demanding action against several government departments on issues of public interest, I have proactively done my statutory work fearlessly and dutifully," she said in her letter.

She has sought action and support so that all those who are trying to intimidate her, are taught a lesson.

"It is very shocking and disturbing for me. Thankfully I and my family were not home so he was not able to harm us. I have lodged a complaint with Delhi Police. Any threat or attack will not stop me from performing my duty. I shall continue to work fearlessly and actively on issues related to women's rights and shall not allow any vested interests to deter me from doing my statutory work," she asserted.

Deputy Commissioner of Police (North) Sagar Singh Kalsi said on reaching the spot, the police team found a person, who was detained in connection with the incident.

The accused is under prescription from the Institute of Human Behaviour and Allied Sciences (IHBAS), he said.

In the wake of the attack, Chief Minister Arvind Kejriwal has urged Lieutenant Governor V K Saxena to take steps to improve the law and order situation in the national capital, which has deteriorated in the last few months.

"In the last few months, the law and order situation of Delhi has been in a bad state. Even the chairperson of Delhi Commission For Women is not safe. Murders are happening in broad daylight. I hope that LG sir will spare some time to repair the law and order situation," he said in a tweet in Hindi.

Last week, the DCW chief alleged that she received rape threats on Instagram after she wrote to Union Information and Broadcasting Minister Anurag Thakur demanding the ouster of filmmaker Sajid Khan from a reality show in the wake of multiple sexual harassment allegations against him.

A majority of allegations against Khan surfaced during the #MeToo movement.