Last week, the construction company had sought protection for the engineers after receiving a demand for ransom.
One person has been arrested today in connection with the killing of two engineers of a private road construction company who were shot dead in Bihar's Darbhanga district on Saturday.
A cop was also suspended on Saturday and the probe was handed over the State's Special Task Force. Just a week ago, the two engineers had received calls for ransom, the police said.
According to the police, two men on motorcycles attacked the project engineers - Brajesh Kumar and Mukesh Kumar - while they were supervising road construction at Darbhanga-Kusheshwarsthan highway.
Both were taken to a hospital where they were declared dead, Deputy Superintendent of Police Dilnawaz Khan said. Police suspect that they were killed for not paying ransom.
Last week, the construction company had sought protection for the engineers after receiving a demand for ransom. The police had responded by deputing policemen to stand guard at the construction site.
But the policemen were removed from the post on Friday and were not present when the attack happened.
"Those who are responsible for this will not be spared. They will be caught and will be put behind the bars. Compromise will not be done. Law and order is our speciality," Janata Dal (United) spokesperson Dr Ajay Alok said on Sunday.