Security has been beefed up at the airport here following an alleged bomb threat issued through e-mail, police said on Thursday..The airport security and police restored to thoroughly frisk the passengers in the wake of the threat..Sniffer dogs were brought to detect any suspicious objects. An investigation was on, the official said..Kapil Sharma, Remo D’Souza, Rajpal Yadav Receive Threat Mails; FIR Filed