Chaos broke out at Karkardooma court complex on Tuesday afternoon, as seven prisoners armed with surgical blades attacked policemen inside the court complex lockup.
The prisoners attacked the policemen while a forcible physical search was being conducted on them.
"Initially, they declined the physical search and warned the policemen inside the lock up with dire consequences," said a senior police official.
As the scuffle broke out between them, several policemen guarding the complex rushed to the lock up. The police also recovered contraband substances along with surgical blades from the prisoners.
Five constables sustained minor injuries in the attack.
A case of obstructing public servant performing his duty has been registered at Anand Vihar police station.