The police have tightened security around popular comedian Raju Shrivastava after he received threat calls from Pakistan for making fun of underworld don Dawood Ibrahim, the entertainer's manager said here Friday.

"Over a month ago, Raju received several threatening calls. The anonymous caller warned him of dire consequences if he did not stop poking fun at Pakistan and cracking jokes on Dawood Ibrahim on his TV shows and stage programmes, " Raju's business manager Rajesh Sharma told.

Initially, Raju and his family - who live in Oshiwara here - considered these as crank calls and did take them seriously. In the past one month or so, however, Raju received over 10 such calls, Sharma added.

The crime branch, which apparently has tapped the calls, has provided additional security to the comedian.

"A few months ago, Raju had received some local threats and he was given police security for a brief period, " said Sharma.

Raju, who started in Bollywood playing bit roles, achieved national fame after winning STAR One's "Laughter Challenge" show a couple of years back. He is now a regular on several comedy shows on TV channels as well as stage shows all over India.