At least nine passengers were killed when a remote-controlled bomb struck a bus in Afghanistan today, police said.
The militant who set off the device was spotted running away from the scene just north-west of the capital, Kabul, and was captured by local villagers.
The bomb had been placed under a bridge and was detonated when the bus drove over the span, said Mohammad Zahir, the criminal director for Kabul police.
Broken glass and abandoned shoes of victims littered the road near the bus, which was turned on its side at the site of the explosion in Paghman district of Kabul province.
At least three other people were injured in the blast, which happened at around 7am local time, as Afghans were making their way to work.
"The person who pushed the button on the remote-controlled bomb was captured by villagers who saw him running," said Abdul Razaq, an Afghan police official in the Kabul area.
Initial reports said the bus was ferrying government employees to an Afghan ministry, but those reports could not be confirmed.
Police speculated that the bomber might have tried to target a bus full of government workers but blew up a civilian bus by mistake.
Paghman district police chief Colonel Amrullah said the explosion killed nine people, including two who were rushed to a local hospital but died within hours. He said three others were wounded.
No-one immediately claimed responsibility for the attack, but Col Amrullah blamed insurgents affiliated with the Taliban. Like many Afghans, he uses just one name.
"It was planted by the enemy of the country," Col Amrullah said of the bomb. He added that police had seized the bomb's remote control from the man who was captured.
Roadside bombs are one of the Taliban's favourite weapons to target Afghan government forces and foreign troops, and they are a leading killer of ordinary Afghans.
Last year was the deadliest on record for civilians in the 10-year-old Afghan war, with 3,021 killed as insurgents stepped up attacks, according to the United Nations.
Also today, the Nato-led international military coalition said one of its service members had died after an insurgent attack in eastern Afghanistan early this morning.
It gave no further details. Nato policy is not to identify the dead until family members have been notified.
Meanwhile, police said a truck bomb has rammed into the gate of a Nato base in eastern Afghanistan.
An official said several Afghans were injured in the blast but no deaths have been reported so far.
The Taliban claimed responsibility for the attack.
The police chief of Logar province said a suicide attacker rammed the explosives-laden pick-up truck into a gate at the Nato base near the provincial capital.
He said at least 11 Afghan civilians were wounded. There was no word of any casualties among international troops.
The police chief, Ghulam Sakhi Roogh Lawanay, said the truck belonged to a local contractor who was authorised to work at the base.
Taliban spokesman Zabiullah Mujahid said insurgents launched the attack.