A murder accused was attacked by another inmate with a pair of scissors inside the Thane Central Jail, police said.
Aftab Hussain Khan (25) was injured in the attack Tuesday afternoon.
Aftab, arrested by Malvani police in Mumbai in an alleged case of murder, had been assigned a stitching job in tailoring department of the prison, a police official said.
According to the preliminary probe, he was humming a song when Mejabuddin Yakub Khan, another inmate, thought that Aftab was abusing him, leading to a spat.
Mejabuddin allegedly picked up a pair of scissors and attacked Aftab, hitting him on the forehead.
Aftab was taken to the jail hospital where he received a dozen stitches, the police official said.
A case under IPC section 326 (causing grievous hurt by means of dangerous weapons) was registered at Thane Nagar police station against Mejabuddin and further probe is on.