Bengaluru, Dec 15 (IANS): Bengaluru has been put of high alert Monday following tweets on Twitter threatening a repeat of the hostage drama at a cafe in Australia's Sydney, Karnataka Home Minister K.J. George said.

"A high alert has been sounded in Bengaluru after police received tweets on its Twitter account threatening to re-enact a Sydney-like hostage drama in the city," George told reporters at Belgavi, about 500km from here, where the 10-day winter session of the state legislature is underway since Dec 9.

The latest terror threat came after a city police officer received a threat tweet Sunday from an unknown Twitter account for arresting Islamic State (IS) terror group's radical supporter Mehdi Masroor Biswas from the city Saturday.

"All police officers in the city have been put on high alert and told to step-up vigil to prevent any untoward incident, check suspicious movements and beef up security in sensitive areas and at vital installations," city Police Commissioner M.N. Reddi told reporters here later.

With an Indian employee of global software major Infosys being one of the hostages held by the unidentified gunman in a Sydney cafe, police directed hotels, pubs, cafes, malls, multiplexes and IT firms to ensure safety and security of their employees and guests.

"We have received threatening tweets as our Twitter account (hashtag) is in public domain. We have asked Twitter's Indian arm to submit details, as the volume of data is huge, especially pertaining to Mehdi's tweets on IS activities in Iraq-Syria," Reddi said.

Meanwhile the National Intelligence Agency (NIA) has joined the crime branch's investigation team to interrogate Biswas, who is in five day police custody over his virtual and actual relations with the IS terror group.