A cop checks an unattended bag near Raj Bhavan on Thursday. Picture by Sanjoy Chattopadhyaya

Calcutta police are expanding the security net by asking corporate houses to strengthen their internal vigil and issuing recommendations to government offices, including the civic headquarters.

The Lalbazar authorities wrote to the top bosses of around 50 corporate houses across the city, asking them to instal security gadgets in their establishments and train their guards in using them.

“We have asked them to maintain a record of the entry and exit of visitors and instal closed-circuit cameras at unconventional places like parking lots and pavements in front of the offices. They must also train their guards in monitoring CCTV footage,” said Vineet Goyal, the deputy commissioner of police, (headquarters).

Senior officers during the day took stock of the security preparedness of various offices, including the civic headquarters.

Police commissioner Gautam Mohan Chakrabarti met civic commissioner Alapan Bandyopadhyay and suggested some “short-term and long-term” measures to boost security.

The Calcutta Municipal Corporation (CMC) has decided to hire private guards for New Market, Gariahat Market, Lake Market and water supply and drainage installations in Tallah, Palta and at Auckland Square. Around Rs 50 lakh has been allocated for buying gadgets like door-frame and hand-held metal detectors.

“The CMC’s present security system has become obsolete. The recent blasts in Bangalore and Ahmedabad are an eye opener for us,” said Bandyopadhyay.

The police brass also asked the special branch and the intelligence wing to keep a tab on strangers.

“Officers have been asked to activate their source network and to collect intelligence from residents,” said joint commissioner (administration) Pradip Chatterjee.

The police commissioner and the director-general of police, A.B. Vohra, met the GOC (Bengal area) during the day and discussed intelligence sharing mechanisms.

Despite the multi-pronged attempt to boost security, bomb scare and hoax calls continued on Thursday.

The bomb disposal squad at Calcutta airport had to be called in twice after a bag and a tiffin-box were found lying unattended.

The employees of custom’s godown in Mangoe Lane received a hoax call around 12.50pm.