KABUL, Aug 29: At least 17 people including children died in two explosions within 24 hours in Kabul on Sunday and overnight at a madressah in a south-eastern province of Afghanistan, officials said on Sunday.

The Taliban militia claimed the Kabul bombing, which a spokesman from President Hamid Karzai's office said killed two US nationals, two Afghans and three Nepalis in front of the offices of an international security company.

Taliban spokesman Abdul Latif Hakimi said the bomb was detonated by a Taliban fighter using a remote control device. "A few minutes ago he phoned our chief ... to say that he finished his mission and is alive," Abdul Hakimi said.

The blast in the upscale Shar-i-Naw area of Kabul, where dozens of aid agencies are also located, injured an unspecified number of other people and destroyed several vehicles, an Afghan official said. Afghan police cordoned off the blast site as ambulances rushed to the area to shift injured people, witnesses said.

MADRESSAH BLAST: At least nine children and one adult were killed in a separate blast, which ripped through a madressah in Paktia province on Saturday night, a US military spokeswoman said.

"There were four children, five teenagers and one adult killed," Master Sergeant Ann Bennett said from the US military press centre in Kabul. She said an eight-year-old boy injured in the madressah explosion was being treated at a US military base, but she was unsure how many more wounded there were.

"The explosion took place last night inside a private madressah," Paktia Governor Haji Asadullah Wafa told Reuters by phone. The madressah was in the village of Naiknaam, near the town of Zormat, 125km south of Kabul, according to the Pakistan-based Afghan Islamic Press agency.

The premises were also used by a non-government organization for teaching Afghan women. Paktia's governor said there were contradictory reports about the cause of the blast, with some saying it was an explosive device placed on a motorcycle parked outside the madressah and others saying a device was planted inside the premises.