A suicide bomber detonated an explosives-filled car close to a NATO and police patrol near the Afghan capital on Saturday, wounding at least two Afghan passers-by, police said.
NATO's International Security Assistance Force could not immediately confirm the attack in the province of Logar, which came hours after a bomb hit an army vehicle in Kabul but caused no casualties.
The suicide attack shattered the passenger car carrying the bomb but did not affect the patrolling troops, a local police commander, Abdul Majid Latifi, said.
Two passers-by were injured, he said. The blast was in Charkh district about 70 kilometres south of Kabul.
"It was a suicide bombing carried out by the enemies of Afghanistan. The attacker was killed but thank God the troops were not hurt," Latifi said.
The interior ministry, which handles police matters, confirmed the attack but had no details.
The officials were not able to say who might have been behind the attack but similar ones have in the past been blamed on the Taliban extremist movement, which has claimed most of around 100 suicide blasts in the country this year.
Suicide blasts spiked this year but have dropped off in recent weeks.
A separate attack in the capital earlier in the day was also the first in weeks.
The bomb struck an Afghan army pick-up truck carrying Afghan National Army officers, police criminal investigation chief Alishah Paktiawal said.
"An ANA car was struck by a bomb but luckily there were no casualties," he told the agency.
The explosive device had been planted at the side of the road and was remotely detonated, one of the occupants said, refusing to give his name because he was not authorised to speak to the media.
"The front of the cabin is damaged but nobody has been wounded or killed," the officer said.
Paktiawal said the attack was "another attempt by enemies of peace and stability to destabilise Afghanistan".
The term is generally used to refer to the Taliban movement, which launched an insurgency after being toppled from government five years ago.
Other groups are however also involved in regular unrest in Afghanistan.
The interior ministry said meanwhile that 12 alleged Taliban were captured on Friday in southern Uruzgan province.
They included an alleged area commander and an intelligence chief, the ministry's media office said.
Afghanistan has this year gone through the bloodiest phase of the insurgency with around 3,700 people killed, four times the number last year.
Most of the dead are insurgents but around 1,000 civilians are also estimated to have died.