Image caption The gates to the base are often busy with queuing trucks and cars

At least seven civilians have died in a suicide attack at an airport used by international forces in the southern Afghan city of Kandahar, officials say.

The attacker, driving a car, detonated explosives close to a gate at the perimeter of the airport.

Nato says none of its personnel was killed. Afghan officials say the victims included two children.

The Taliban told the BBC it was behind the attack, which analysts say shows Kandahar's fragile security situation.

A series of recent attacks has shattered a relative peace enjoyed by Kandahar - seen as the spiritual home of the Taliban, as well as being the birthplace of Afghan President Hamid Karzai.

Earlier this month, a series of blasts killed at least 12 people in the city.

Officials say Thursday's attack - which happened at about 13:15 local time (08:45 GMT) - was aimed at foreign forces stationed at the airfield.

Police initially said the suicide bomber had arrived on foot, but the interior ministry later said the attacker had been driving a Toyota Corolla.

Zalmai Ayubi, a spokesman for Kandahar's provincial governor, said eight other civilians had been injured, including two children.

'Dust everywhere'

Gates to the larger US bases in Afghanistan are often crowded with trucks waiting to deliver goods as well as local residents going to or from work on the compounds.

A truck driver, named only as Safiullah, said he had been waiting his turn to enter the base when the blast occurred.

"There was dust and smoke everywhere," he said.

"I got down on my knees. When the smoke lifted, I moved closer. I saw two children dead at the side of the road."

A Nato-led coalition of foreign forces has been in Afghanistan for more than a decade.

Last year, US President Barack Obama announced that tens of thousands of US forces would be withdrawn by 2013 - though 68,000 will remain of the current US force of 90,000.

Nato has started handing over security responsibility to Afghan forces in several provinces.

However, according to the UN, the number of casualties in continuing violence in Afghanistan has increased.

On Wednesday, a suicide attack and roadside bomb in Helmand province - which neighbours Kandahar to the west - killed 13 people.

A senior security official and tribal elder were among those killed by the roadside bomb, which the Taliban said it carried out.