A NATO soldier has been killed and another is "presumed dead" after a battle between insurgents and Western troops in southern Afghanistan Tuesday, while two firefights in the east killed two US and four Afghan troops, officials said. The clashes came as NATO prepared to assume military command of eastern Afghanistan from a US-led coalition. A suicide bomber on a motorbike meanwhile attacked a Canadian military convoy in the city of Kandahar, but no troops were injured, said Maj. Daryl Morrell, a spokesman for the NATO-led force.