She was being briefed by ex-MI5 officers who came into the palace to advise her on her security.

BBC: Full text: Burrell interview

The trial in Pretoria's Palace of Justice is surrounded by the highest security for a court case in more than a decade.

BBC: South African treason trial starts

While security at such sites as Buckingham Palace, the Houses of Parliament and London's Canary Wharf has been stepped up, efforts to counter terror attacks are by no means as visible in the UK as they presently are in United States.

BBC: Met chief learns NY terror lessons

The same security is in place at the Topkapi Palace, the jewel in the city's crown and its top tourist attraction.

BBC: NEWS | Europe | Tourists defy Istanbul bombers

Estrada claims he is attending to callers who cannot go to the palace for fear of being turned away by presidential security.

CNN: ERAP'S BIG ROLE

During the news conference at the presidential palace, Karzai also discussed ongoing negotiations on a U.S.-Afghan bilateral security agreement.

NPR: 7 American Service Members Killed In Afghanistan

Governors from Mexico's 21 states and the federal district of Mexico City, mayors, judges, prosecutors and senior police and security officials were at the meeting hosted by President Felipe Calderon at the National Palace.

BBC: Mexico to combat rising violence

The top security "red zone" includes the city centre, the summit venue, the 13th-Century Ducal Palace, and the waterfront where hotels and cruise ships hosting 1, 500 delegates and 5, 000 journalists will be located.

CNN: Genoa braces for G8 summit