A NATO soldier was killed escorting a convoy in southern Afghanistan on Sunday, while four Afghan security guards died in a suicide attack. NATO did not disclose the soldier's nationality or the exact location of the incident. A Taliban insurgency is raging in Afghanistan's south and attacks on supply convoys are near-daily occurrences. Meanwhile, a suicide bomber blew himself up next to members of a private security company providing protection for a road construction company Saturday in southern Helmand province's Lashkar Gah district. Four guards were killed and three others wounded, said provincial police chief Mohammad Hussein.