RAWALPINDI, Jan 2: The Indian security officials are bringing in a special device to further boost security for their prime minister during the Saarc summit, a security source told Dawn.

The device known as "Initiator" can detect and detonate any explosive device or material before time thus preventing it from hitting the target. The source said the device moved ahead of the VVIP convoy and detected any explosive device.

Whereas the "jammers" usually fixed in the VVIP vehicles have the capacity to delay an explosion as had happened in the first attempt on President Musharraf on December 14.

Earlier, the Indian government had air-lifted three bullet- proof BMW cars into Islamabad for the use of Indian Prime minister Atal Bihari Vajpayee during his stay here.

In another related move, Prime Minister Mir Zafarullah Khan Jamali on Friday inspected a full-dress rehearsal of security arrangements for the Saarc summit. The sensitive areas would be given security clearance at midnight after complete sweeping and cleaning by the sniffer dog squad, bomb detection teams and under-cover security officers, a security source said.

At least 14 sniffer dogs provided by the Rangers and III Brigade will take part in the sweeping operation, the source said. A security official told this reporter that they had been directed to shoot anybody breaching the security cordon.

AFP ADDS: Massive security clampdown went into top gear here on Friday for the forthcoming Saarc summit as army helicopters buzzed low over the Capital, which resembled a city under siege.

Around 10,000 paramilitary troops and police are manning a heavy security blanket around normally sleepy Islamabad. Roadblocks have been erected at all entry points to the city where passers-by were being frisked and vehicles checked for bombs.

A "red zone" covering a radius of around 2km has been established around the two main hotels where heads of state and senior delegates are staying, and the Convention Centre where opening and closing ceremonies will be held.

"It is one of the most stringent security operations in the history of the country," said a senior security official. Anti-aircraft guns and troops have been positioned in the Margalla hills overlooking the city while popular hiking and jogging tracks have been declared out of bounds. All schools, colleges and religious seminaries will remain closed for a week.

Security for the summit became the top concern after two attempts to assassinate President Pervez Musharraf in Rawalpindi. The last attack came on Christmas Day when two suicide bombers rammed their explosives-laden vehicles into Musharraf's motorcade, killing 16 people but missing the president.

Refusing to be scared off but taking no risks, India sent two bullet-proof limousines and a squad of its crack 'Black Cat' commandos for Prime Minister Atal Behari Vajpayee, a Pakistani security official said.

Vajpayee is due to arrive Saturday evening aboard a special plane. Officials said similar limousines had been arranged by Pakistan for the five other visiting heads of government.