The Taliban has launched a suicide car bomb attack on a Nato military convoy in Afghanistan's capital, Kabul, killing two people and wounding 26 others.
The blast sent a huge plume of black smoke over the city and scattered glass and metal across the main highway to Kabul's airport.
Kabul deputy police chief Sayed Gulagha said a suicide bomber struck the convoy with a vehicle packed with explosives.
Interior ministry spokesman Sediq Sediqqi said two Afghan civilians were killed and at least 24 wounded, some critically.
A spokeswoman for Nato's Resolute Support mission in Afghanistan, US Army Capt Susan Harrington, said two American soldiers sustained minor injuries in the attack.
The Taliban claimed responsibility for the bombing, the latest in a series of attacks in recent months targeting foreign convoys, hotels and residences used by foreigners in Kabul.
At least two of the convoy's armoured vehicles were badly damaged in the explosion, which happened less than half a mile from the American Embassy. Embassy spokeswoman Heather Eaton said all personnel were accounted for.
Witnesses said the attack happened during early afternoon prayers, and that people who rushed out of a nearby mosque had turned on the foreign soldiers and journalists, throwing stones at them.
The attack took place during the afternoon rush hour, when roads were choked with employees returning home. The work day has been shortened for the holy month of Ramadan, when Muslims fast from dawn to dusk.
"I saw a Toyota Corolla target the convoy of foreign forces," eyewitness Ahmad Farhad said.
"I saw two to three damaged vehicles, and wounded victims were everywhere, and there was no-one to help them."
Last week the Taliban launched an audacious attack on parliament. Security forces managed to fend off the attack, and no lawmakers were wounded, but the assault highlighted the ability of the insurgents to penetrate the heavily guarded capital.
Meanwhile, Afghanistan signed an extension to a long-running UN police support programme that will transfer some 900 million dollars (£570 million) to the government over the next 18 months.
The Law and Order Trust Fund for Afghanistan, set up in 2002, has been plagued by accusations of waste and corruption. The interior ministry's spokesman, Najib Danish, said the deal sets benchmarks for reviews every six months.
The agreement with the UN development programme will channel approximately 843 million dollars (£536 million) to pay the salaries of more than 150,000 police officers, and 38 million dollars (£24 million) for broader security and justice reform.
Police are particularly vulnerable in the fight against insurgents, and are suffering a spike in casualties as they are often the target of Taliban attacks on flimsy checkpoints in remote districts.
A suicide attack on the police headquarters of southern Helmand province killed three people and wounded more than 50, including policemen, police spokesman Farid Hamad Obaid said.
Omar Zawak, spokesman for the governor of Helmand province, said most of the wounded were women and children.
In the eastern Paktya province, three people were killed and one wounded on Tuesday when their vehicle hit a roadside bomb, provincial police chief Zalmai Oryakhel said.