World Photos - Reuters

A Royal Air Force Chinook CH-47 helicopter carrying Royal Marines from 42 Commando, is seen preparing to land in Afghanistan in this October 10, 2006 handout photograph, and released by Britain's Ministry of Defence in London December 15, 2009. Britain said on December 15, 2009, it was buying 22 Chinook military helicopters to increase air support for its troops in Afghanistan. REUTERS/MoD/Sean Clee/Handout (AFGHANISTAN - Tags: MILITARY CONFLICT POLITICS TRANSPORT) NO ARCHIVES. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS