A bomb rigged to a motorcycle was detonated as a police vehicle was passing from the market of Kunduz City [AFP]

Two separate attacks in Afghanistan have killed at least 10 people, among them four Afghan police officers.

A suicide car bomber killed three civilians, including a child, and wounded several others when he rammed his vehicle into an Nato convoy in Kandahar on Saturday.

"I was walking along this road when suddenly I heard a huge explosion and I started running away, after a few minutes I went to the blast site, I saw three people had died and eleven others were wounded," John Agha, an eyewitness at the site, said.

About a dozen people were injured in the attack. There was no immediate information about possible Nato casualties.

"Obviously they [the Taliban] do continuously attack foreign forces throughout the country but there was no direct claim of responsibility," Al Jazeera's Hoda Abdel-Hamid, reporting from Kabul, the Afghan capital, said.

Kunduz bomb

Earlier on Saturday, seven people were killed and 16 others injured in an attack in the northern Afghan province of Kunduz.

Sources told Al Jazeera that the explosion took place in front of a butcher shop supplying the local police in the Bander Imam area of Kunduz city.

"The bomb rigged to a motorcycle detonated as a police vehicle was passing from the main market of the city," Muhammad Omar, the governor of Kunduz, said.

Abdel-Hamid said at least seven people were killed in the attack, including four police officers.

Kunduz is a major transportation hub and lies along a crucial supply line for coalition forces that has been repeatedly attacked by Taliban fighters.

Fighters have stepped up attacks on police and civilians in Kunduz in an apparent attempt to destabilise local authorities.

While there was no immediate sign of a connection, the bombing came on the first anniversary of a Nato warplane attack on two fuel trucks just outside Kunduz city that killed as many as 142 people, the single largest loss of civilian lives since the 2001 US invasion of the country.

Afghan officials repeatedly warn that such incidents undermine the central government in Kabul and fuel support for its Taliban opponents.

Also on Saturday, Nato announced the capture of a Taliban commander and the killing of six fighters in a raid on their hide-out in the northern province of Takhar.

The attack followed a string of recent raids on Taliban leaders that aim to demoralise the Taliban and sever contacts between armed groups.

Source: Al Jazeera and agencies