Two US soldiers were killed in an attack in southern Afghanistan, the military said Tuesday, the latest in a surge of Western military casualties as violence rises ahead of elections next month. NATO said the troops were from its International Security Assistance Force (ISAF) and were killed "as a result of hostile incident in southern Afghanistan." It gave no further details, but a spokesman for a separate US-led coalition told a foreign news agency that the victims were US nationals. About 4,000 US Marines are battling insurgents in a massive offensive launched in the south early this month to clear Taliban militants out of strongholds ahead of presidential and provincial council elections scheduled for August 20.