Seven construction workers were hospitalised after 20 masked men attacked them with iron rods and sticks at the upcoming convention centre-cum-food plaza at Kadma on Wednesday night.

The convention centre, which is being set up at a cost of Rs 10 crore by Jharkhand Urban Infrastructure Development Company (Juidco), is located near the house of the Congress’s Jamshedpur West candidate Banna Gupta.

The seven injured — one of them has suffered multiple hand and head injuries — were admitted to MGM Medical College & Hospital.

Eight others were released after first-aid.

Those undergoing treatment at the hospital are Pyara Singh, Ranjit Kumar, Sachin Prasad, Raju Singh, Ram Niwash, Jitendra Kumar and Bhup Singh.

“The workers used to sleep in the under-construction building at night. Around 10pm on Wednesday, while they were preparing to sleep, around 20 masked men entered the building and started beating them with sticks and rods,” project manager Utkarsh Pandey said.

He said several workers jumped from the first floor of the four-storey building to escape the attackers.

Pandey, who lives in Shastrinagar in Kadma, rushed to the spot and took the injured to the hospital.

Around 25 workers were present at the site when the attack took place. Only 10 turned up for work on Thursday.

Deputy superintendent of police (headquarters-II) Arvind Kumar visited the spot on Thursday. “The attackers did not rob the victims. We are trying to find out the intention behind the attack,” Kumar said.

The land where the convention centre-cum-food plaza is being set up belonged to Tata Steel, but Banna Gupta had constructed a boundary wall at the plot when he was the Jamshedpur West legislator in 2009.

After Saryu Roy was elected on a BJP ticket in 2014, he cleared the land of encroachment and recommended the setting up of a convention centre-cum-food plaza.

Chief minister Raghubar Das had laid the foundation stone of the project last year.