ARLINGTON, VA - MAY 17: Family, friends and colleagues follow the casket of U.S. Army PFC Michael Metcalf during his burial service at Arlington National Cemetery May 17, 2012 in Arlington, Virginia. Metcalf, from Boynton Beach, Florida, died April 22 in the Paktia province of Afghanistan when a vehicle he was driving ran over an improvised explosive device.
ARLINGTON, VA - MAY 17: Clarence Metcalf (C) holds the American flag that was draped over the casket of his son, U.S. Army PFC Michael Metcalf, during a burial service for PFC Metcalf at Arlington National Cemetery May 17, 2012 in Arlington, Virginia. Metcalf, from Boynton Beach, Florida, died April 22 in the Paktia province of Afghanistan when a vehicle he was driving ran over an improvised explosive device. Also pictured is PFC MetcalfÕs mother, Kimberly Metcalf (L).
ALTON, HAMPSHIRE - MAY 18: Royal Navy air crew stand beside a Sea King (R) and two Merlin helicopters at RAF Odiham air base ahead of a rehearsal for a Diamond Jubilee flypast on May 18, 2012 near Alton, England. The armed forces are paying tribute to Her Majesty Queen Elizabeth II in a Parade and Muster event at Windsor Castle on May 19, 2012. The RAF, Royal Navy and Army will take part in a flypast of 73 aircraft including a World War II Lancaster bomber and four Spitfires.
ALTON, HAMPSHIRE - MAY 18: A Royal Navy Pilot sits inside a Lynx helicopter at RAF Odiham air base ahead of a rehearsal for a Diamond Jubilee flypast on May 18, 2012 near Alton, England.
LONDON, ENGLAND - MAY 18: A general view of the HMS Belfast ahead of its re-opening to the public on May 18, 2012 in London, England. The Second World War Royal Navy warship, a popular tourist attraction on the River Thames, closed to the public in November 2011, after a section of the gangway which provided access to the vessel collapsed.
LONDON, ENGLAND - MAY 17: Members of the military Brass Band play during a training exercise at Wellington Barracks on May 17, 2012 in London, England. The tri-Service Guard of Honour trained with the Band at Wellington Barracks ahead of their participation during the Royal celebrations at Windsor on May 19, 2012.
A Carabiniere, left, and an Italian army soldier check a tourist with a metal detector outside the Duomo cathedral in Milan, Italy, Thursday, May 17, 2012. Italy increased security Thursday at 14,000 sites, and assigned bodyguards to protect 550 individuals after a nuclear energy company official was shot and letter bombs directed to the tax collection agency.
Congolese government army soldiers carry weapons and mortar equipment on the road to the border town of Bunagana, after their unit returned from the frontline of fighting against rebel forces, in Kinyamahura, Congo Thursday, May 17, 2012. A new rebel group believed to be led by former warlord Bosco Ntaganda, who has been indicted by the International Criminal Court for war crimes, is now fighting the Congolese government in the east of the country. Ntaganda is sought on an international arrest warrant for his alleged use of child soldiers during an earlier conflict, and has forcibly recruited another 149 boys and teenagers since April 2012, according to a Human Rights Watch investigation.
Lebanese soldiers take position in Tripoli's Sunni neighbourhood of Bab al-Tabbaneh on May 17, 2012. Fresh sectarian clashes erupted between pro- and anti-Syrian districts in the north Lebanon port city of Tripoli, leaving at least one person dead and seven wounded, a security official said.