Security forces have arrested the suspected organizer of the deadly car-bombing of a U.S. security firm and believe he was acting on the orders of Al Qaeda, an Afghan official said Saturday.

The man, a Tajik national called Mohammed Haidar (search), confessed his leading role in the Aug. 29 car-bomb attack, which killed about 10 people, including three Americans, Afghan state television reported.

A spokesman for the Afghan intelligence service, Mohammed Nader (search), said the report was accurate but declined to discuss the details.

Haidar also admitted organizing a suicide attack on a Kabul shopping street on Oct. 23, which killed an American woman and an Afghan child, the TV report said. The attack was allegedly carried out by a Kashmiri (search) militant.

Afghan officials have released no details of their investigations into the two attacks, though an American general has suggested the car-bomb was the work of a militant group with links to Usama bin Laden's Al Qaeda network.

It was unclear when Haidar, a bearded man of about 30 shown briefly during the evening news, was detained.

The report said Haidar told investigators that he had traveled to the Pakistani city of Peshawar to meet an alleged Al Qaeda member called Attaullah who gave him the instructions to carry out the attacks.

Attaullah supposedly paid Haidar $7,000 to buy a car and explosives, the report said. It didn't say when the meeting supposedly took place.

The car bomb devastated the main office of Dyncorp, a private security contractor which supplies bodyguards for Afghan President Hamid Karzai and is training the country's police force.

The suicide attack, carried out by a young man laden with hand grenades, apparently targeted a group of Icelandic soldiers as they visited a carpet store. Three of them were slightly injured.