The phone call was received by the security wing in the afternoon. The caller claimed that a bomb has been kept in the 'C' Block of the Secretariat which houses the CMO, police said.
Senior police officials and bomb disposal squads swung into action and began searches at the CMO, they said. Chief Minister K Rosaiah, several ministers and top officials were attending a video conferencing inside the conference hall of the Secretariat, while the searches were on, police said.