Authorities in Afghanistan say attacks by suspected insurgents have killed three people and wounded at least eight others.

Police say a roadside bomb Saturday in Kandahar province killed three Afghan security guards and wounded at least two others.

Bomb Attacks Kill 3, Wound 8 in Afghanistan

In another incident, Afghan officials say six people, including two foreigners, were wounded Saturday when a suicide car bomb exploded near a vehicle convoy traveling through the capital, Kabul. The nationality of the wounded foreigners is not yet known.

Bomb Attacks Kill 3, Wound 8 in Afghanistan

There has been no claim of responsibility for either attack.

Bomb Attacks Kill 3, Wound 8 in Afghanistan

In the past year, insurgent violence has sharply increased in Afghanistan's south, which is a stronghold of the hardline Taleban, ousted from power by American forces six years ago.

Meanwhile, the U.S. State Department says it is investigating a friendly fire incident in southern Helmand province that killed three British soldiers and wounded two others.

Britain's Defense Ministry says its soldiers were killed by a U.S. air strike. Officials say the incident occurred late Thursday after warplanes were called in to support the British troops battling Taleban insurgents in Helmand.