Afghan officials say a roadside bomb has killed four people in the southern province of Helmand.

The officials say Afghan police discovered the bomb Monday in the Nadi Ali district, but the device exploded before they could defuse it. The dead include two policemen and two civilians. Another four civilians were wounded.

Also today in the south, Afghan officials say a suicide bomber on a motorcycle struck a police vehicle in the Spin Boldak area of Kandahar province, wounding five policemen.

In other violence, the U.S.-led coalition says a roadside bomb killed one coalition soldier and wounded two others today in the Kot district of the eastern province of Nangarhar. The coalition did not specify the nationality of the casualties.

Canada also announced today that two Canadian soldiers serving with NATO forces were killed in an accident Sunday in Kandahar. Ottawa says the soldiers' armored vehicle rolled over while crossing difficult terrain in the Zhari district.

Separately, the NATO alliance says a battle between NATO troops and Taliban militants in Uruzgan province last Friday left two civilians dead. NATO says the fighting began when militants attacked its soldiers with a roadside bomb.

NATO expressed regret for the deaths of the two civilians, one of whom was a child.

Some information for this report was provided by AFP and AP.