A suicide car bomb attack targeting NATO troops in the Afghan capital on Tuesday killed more than 20 civilians in one of the deadliest strikes in Kabul in months, an army doctor said.

The bomber detonated in western Kabul during the busy rush hour, close to an army recruitment centre and a hospital, but the Afghan interior ministry said NATO's International Security Assistance Force (ISAF) was the target. "We have five bodies brought to our hospital so far... the number of the dead is more than 20, all civilians. The death toll is very high," Afghan army chief doctor General Ahmad Zia Yaftali said.