"A group of around 25 men barged into the office of Yusuf A Zojwalla (70) in Kolsewadi area last night and demanded the money. They attacked supervisor Sanjay Mirkute with iron rods," said inspector N S Mhaske of Kolsewadi police station.
The accused threatened the builder against carrying out work at one of his ongoing construction sites, and uprooted CCTV cameras before leaving, he said.
A case has been booked against unknown persons under various sections of IPC.