NATO says an explosion in southern Afghanistan has killed one of its soldiers. The alliance says the soldier died during a security patrol in Lashkar Gah, the capital of Helmand province. Most troops in Helmand are British, but NATO did not reveal the soldier's nationality. June has been the deadliest month for international troops in Afghanistan since the US-led invasion in 2001. An Associated Press count of soldier deaths shows 42 troops have died this month, surpassing the 33 killed in September 2006. 2007 is on pace to be the deadliest year for international troops in Afghanistan since 2001. The AP count shows 117 troops have died so far this year.