UPDATE 2-Two U.S. soldiers killed in Afghan suicide attack

(Adds incident in Zabul province, Taliban website and identity of attacker, background)

KABUL Jan 9 (Reuters) - Two U.S. soldiers were killed in a suicide car bomb attack in south Afghanistan that was claimed by the Taliban, NATO said on Friday.

The attack happened late on Thursday afternoon beside a busy market in Maywand district, Kandahar province, about 400 km (250 miles) southwest of Kabul.

A district police chief told Reuters three civilians were also killed, while NATO identified one dead civilian.

Kandahar, which is a Taliban stronghold, is the headquarters of NATO-led operations in southern Afghanistan, where more than 18,000 mainly Canadian, British and Dutch troops are locked in a fierce battle against insurgents.

The Taliban posted a statement on its website claiming a local Kandahar man, Hafiz Muhammad, carried out the attack.

In a separate incident, U.S. military forces killed two militants and detained three suspected militants during an operation to target a bomb-making cell in the southeastern Zabul province, which neighbours Kandahar. (Reporting by Golnar Motevalli; Editing by David Fox)