QALAT, Afghanistan - Two Afghan children were killed and two people wounded Monday in a blast in the country's southern province of Zabul, said a provincial source.

"Two teenage brothers were killed and their father and sister were seriously wounded when their sedan set off an improvised explosive device (IED) in Asghar Qeli area of the provincial capital at early Monday morning," Deputy Provincial Governor Mohammad Jan Rasoulyar told Xinhua.

He said the injured were admitted to a hospital in the city, 340 km south of the country's capital Kabul.

On Sunday evening, a father and his child were killed and one person was wounded in a similar incident in neighboring Kandahar province.

The official blamed enemies of peace and stability, a term used by Afghan officials against Taliban insurgents, for planting the bomb.

Four children were killed and several injured in IED blasts in the country over the past week.

Afghan Taliban frequently attacks Afghan and NATO-led forces with IEDs but the lethal weapons also inflict casualties on civilians.

The UN Assistance Mission in Afghanistan (UNAMA) has said that more than 1,300 civilians were killed and over 2,500 others injured in Afghanistan from January to June this year.

Out of the total casualties, 231 children were killed and 529 were wounded with IED explosions the leading cause of the fatalities.