KABUL - Five foreign soldiers were killed in an insurgent attack in eastern Afghanistan on Saturday, the NATO-led International Security Assistance Force (ISAF) said in a statement.It was the highest toll of foreign soldiers in a single incident in several months.ISAF gave no details of the location or nature of the attack, but a spokesman for the Defense Ministry said a suicide bomber in an Afghan army uniform had attacked a base, killing four Afghan soldiers and causing some foreign casualties.