An explosion caused by a suicide car bomber in the southern Afghan city of Kandahar has killed at least three people and wounded 17, police say.
The blast went off near a hotel in Afghanistan's second largest city and a former base of the Taliban rebels.
It comes as Nato and Afghan forces are preparing for a joint offensive against Taliban militants in neighbouring Helmand province.
Two US soldiers were killed Tuesday in a bomb attack in the south, Nato said.
"It seems that a suicide car bomb attacker wanted to drive into the main street and has detonated prematurely," a police officer told the AFP news agency.
Previous attacks in Kandahar province have been blamed on Taliban insurgents, who are said to be regularly using suicide car bomb attacks.
The attack comes as the Nato commander in the country Gen Stanley McChrystal said security in Afghanistan remained serious, but was no longer deteriorating.