Security around the office and home of Union Minister for Road Transport Nitin Gadkari, was tightened following extortion-cum-death threats, officials said in Nagpur on Saturday.

At least three calls were received by Gadkari’s private office in the city between 11.30 am and 12.30 pm, and the caller purportedly uttered the name of absconding mafia don Dawood Ibrahim Kaskar.