Officials put up a banner of different constituencies' rooms at a counting centre In Bengaluru. (PTI)

A four-tier security had been put in place for Thursday's counting of votes in all the 28 Lok Sabha constituencies across Karnataka, an official said on Wednesday.

"The four-tier security comprises the central armed police forces in the inner core, armed police at the gate, civil and armed police at perimeter, one platoon of the Karnataka State Reserve Police as striking party and round-the-clock supervision by a deputy superintendent of police," state Chief Electoral Officer Sanjeev Kumar told news agency IANS.

While counting centre for each Lok Sabha seat is at the district headquarters, there are three centres in Bengaluru as it has three constituencies - North, Central and South.

"The fool-proof security arrangements and heightened vigil are aided by door-frame metal detectors, hand-held metal detectors, bomb disposal and dog squads and CCTV cameras for recording the proceedings," Mr Kumar said.

Eight counting centres have been identified as sensitive and central forces have been asked to guard them till the end of counting and declaration of results. "Mobile handsets, laptops or any electronic device that can make audio or video record are not allowed inside the counting centres," said Mr Kumar.

Election Commission's (EC) observers and its officials are exempted from the ban as they require the devices for uploading counting data by Suvidha application.

Entry to the centres is regulated and only authorised election personnel, counting agents and candidates will be allowed inside through entry access passes issued by the district electoral officer.

"All counting centres are secured. Only one gate will be for entry after frisking. No mobiles, cigarettes, match boxes, inflammable material and water bottles will be allowed into the centres," said Mr Kumar.

Outside the centres, the state police will regulate traffic movement, designate parking of vehicles and gathering of public with LED screens. Movement of personnel in the centres will also be controlled.

All the electronic voting machines (EVMs) and the voter verifiable paper audit trails (VVPATs) have been kept in sealed strong rooms under security, CCTV coverage and surveillance of candidates.

At each counting centre, two Deputy Commissioner of Police, six Assistant Commissioner of Police, 22 Inspectors, 23 Sub-Inspectors and 103 Assistant Sub-Inspectors will be deployed to maintain law and order.

"Ban order under Section 144 of the Code of Criminal Procedure will be enforced from May 22 midnight till the counting process is completed," Mr Kumar added.

The police also banned sale of liquor and ordered closure of liquor shops for 24 hours from Wednesday evening till the election results are declared to prevent any untoward incident.

The EC has given eight different coloured T-shirts to polling officials to ensure those deployed for one Assembly segment don't go to any other segment.