Afghan officials: Kabul car bomb killed 12, including children

No one immediately claimed responsibility for the attack, but both the Taliban and the Islamic State group are active in the Afghan capital and have claimed many previous attacks in the city.

The explosion occurred in the Qasaba area, in the Afghan capital's police district 15. The GARDAWORLD security company was the apparent target, according to Nasrat Rahimi, an Interior Ministry spokesman.

The attack also wounded 20, including four of the company's foreign staff, he said but declined to reveal their nationalities.

Reports in the immediate aftermath of the attack said seven had died but Marwa Amini, the ministry's deputy spokeswoman, later released the new death toll in a tweet.

A vehicle belonging to the security company and two private cars were damaged in the attack, Rahimi added and said an investigation was underway into the bombing.

Ambulance sirens were heard shortly after the car bomb went off and a large plume of smoke rose from the area - scenes all too familiar for Kabul and other cities and towns across Afghanistan.

Among those killed were 12-year-old Dunya and her 7-year old brother who were on their way to school. The two children were walking with their father when the car detonated. The father, who was severely wounded and lost a leg and a hand, was in hospital, according to reports on social media.

The Taliban today control or hold sway over half of Afghanistan, staging near-daily attacks that target Afghan forces and government officials but also kill scores of civilians.

In other violence, at least four Afghan army soldiers were killed on Monday night during an airstrike by U.S. forces in eastern Logar province, said Anwar Khan Ishaqzai, the provincial governor. Six other troops were wounded in the attack near Puli Alam, the provincial capital.

The airstrike came as a gunbattle was underway between the army and Taliban insurgents in the area, the governor said, adding that an investigation has started into the strike, which killed and wounded army soldiers by mistake.

A spokesman for U.S. forces in Afghanistan said the coalition was aware of the reports from Logar.

"U.S. and Afghan forces are working closely together to develop a shared understanding of this event. A joint investigation is ongoing" said the spokesman, speaking on condition of anonymity under regulations.

Also on Monday night, five policemen were shot and killed at their checkpoint in western Herat province, said Abdul Ahid Walizada, the provincial police chief's spokesman. Walizada said three other police officers were wounded in the attack in Oby district.