Seven men armed with wooden sticks and iron rods attacked the contractor at the construction site of central jail in Sachin on Friday and decamped with Rs 2.36 lakh and two mobile phones. They also assaulted the contractor’s nephew and a security guard.

According to the police, the miscreants first assaulted security guard Sadur Bharwad when he tried to oppose their entry. Later, they broke open the main door of a makeshift office and overpowered contractor Ramesh Patel and his nephew Mayank Patel. When the two tried to sound an alarm, the robbers sprinkled chilli powder on them.

Three of them entered the next room and broke open the almirah and decamped with the cash, after which contractor Patel informed the police. The Sachin police rushed to the spot with sniffer dogs and took the three injured to a local private hospital. They were discharged after primary treatment.

Later, Patel lodged a complaint of robbery with the Sachin police station. Inspector K R Bhuwa said: “Ramesh Patel had kept Rs 5 lakh to pay salary to his labourers. After paying 125 of them, he kept the remainder amount of Rs 2.36 lakh in the almirah for other expenditures. The labourers also stay at the site in tents. We suspect involvement of some known person.”

Jailor M L Rathod of the Surat sub-jail said the jail, which is being constructed at the Lajpore village, will be the largest in the state with a space for 5,000 inmates. He added that the sub-jail is “overflowing” with inmates.