Naxalites on Thursday demanded extortion money amounting to Rs 1.65 crore from Vishwanath Sharma Construction Company, engaged in building a bridge over Budhi Gandak at Panapur.

The state government had allotted Rs 33 crore to Bihar State Bridge Construction Corporation Limited in 2012. The corporation had awarded the contract to the firm.

Muzaffarpur senior superintendent of police Saurav Kumar said: “Police stations concerned have been asked to keep vigil and probe is on.”

Avinash Kumar, a supervisor of the firm, said: “We have informed the police.”