British helicopters take off from a base in Helmand province May 5, 2009.
Insurgents had launched a series of attacks against Welsh Guards troops during their operation to seize the canal crossings, the British military said, and almost 100 roadside bombs were found and made safe since it began.
(Additional reporting by Golnar Motevalli in KABUL; Writing by Paul Tait; Editing by Sanjeev Miglani and Alex Richardson)