Local gangster Sunny alias Nandi, who was released from jail on interim bail for medical treatment, was found partying with 40 people in south west Delhi's Dwarka, police said on Monday.
On Saturday, police received information that a party was being organised at Shree Shyam Vakita in village Pochanpur, Dwarka by Sunny's associates.
It was also the same day the gangster was released on bail.
Sunny is an accused in a murder case.Later, police conducted a raid and detained 37 people. Sunny and few others managed to escape from the spot, they said.
Police recovered five illegal firearms from Mahesh Sehrawat (24), Keshav Lamba (26), Birju (31), Neeraj (28) and Sajjan (26). These five people, having previous criminal records, were booked under the Arms Act, the officer said.
The gangsters are members of Naveen Khatti gang of Village Mitroan, Najafgargh, he said. They had gathered to celebrate the release of Sunny, police added.