In Afghanistan, six private security guards were beheaded during a bank robbery in northern province of Balkh while Taliban militants carried out a suicide attack outside an airfield in Kandahar today. Sherjan Durani, a police spokesman for Balkh province said someone apparently mixed a poison into the guards' food last night at a branch of Kabul Bank in the northern city of Mazar-e-Sharif. He said the robbers took about $269,000 in U.S. and Afghan currency. The case is being investigated.Meanwhile, a suicide bomber detonated himself outside the main foreign military base in southern Kandahar city today killing himself, but there were no reports of any other casualties. A spokeswoman for NATO-led forces in Kabul said there was small-arms fire outside the base and that the bomber had tried to gain access through one of the gates.