A suicide car bomber struck a Nato convoy in Kabul, killing at least four people, Afghan officials said. In the south, a man wearing an Afghan military uniform turned his weapons on Nato and Afghan troops, killing two Nato service members, the US-led coalition said.
The Taliban promptly claimed responsibility for the Kabul attack, which took place near Darulaman Palace, the bombed-out seat of former Afghan kings on the southwest outskirts of the capital. Nato said there were "several" causalities among its forces and Afghan civilians, but did not provide details.
The attack was the deadliest of three separate incidents Saturday that targeted either the US-led coalition or Afghan government offices in the country.
The Afghan Ministry of Interior said three Afghan civilians and one policeman died in the Kabul attack. The Taliban claim came shortly after the attack in a text message to media outlets.
In the restive south, an area traditionally viewed as the Taliban's stronghold, Nato said a man in an Afghan military uniform turned his weapon on coalition and Afghan forces, killing two. The shooter was killed, the coalition said in the statement that provided no other details.
The bombing on the outskirts of Kabul appeared to target a Nato convoy that included a military bus.
Nato and Afghan forces sealed off the area as rescuers rushed about the attack site, according to an Associated Press reporter at the scene. Two Nato helicopters landed to airlift casualties while coalition troops using loudspeakers ordered bystanders to evacuate the area. Heavy black smoke poured from the bus, which was engulfed in a fireball.
Later, US troops were seen carrying three black body bags from the bus' burned wreckage, which eyewitnesses said had been sandwiched in the convoy between mine-resistant armored coalition vehicles. The troops also were seen carrying a badly charred body from the bus.
The incident was reminiscent of another similar attack on a Nato convoy in May 2010. In that incident, a suicide bomber struck the convoy, killing 18 people, including five American troops and a Canadian. The Taliban, at the time, said the vehicle was packed with 1,650 pounds (750 kilograms) of explosives.
Earlier Saturday, a female suicide bomber blew herself up as she tried to attack a local government office in the capital of Kunar province, a hotbed of militancy in northeast Afghanistan along the Pakistan border.
Abdul Sabor Allayar, deputy provincial police chief, said the guards outside the government's intelligence office in Asad Abad became suspicious of the woman and started shooting, at which point she detonated her explosives.
There were no other casualties in that attack.
Afghan and US-led coalition forces conducted operations earlier this month, killing more than 100 insurgents in an effort to curb violence in rugged areas of Kunar where the coalition and Afghan government have a light footprint.
Farther south along the Afghanistan-Pakistan border, Afghan and coalition forces captured two leaders of the Haqqani network and two other suspected insurgents in Sarobi district of Paktika province, the coalition said.
Haqqani fighters, who are affiliated with the Taliban and al Qaeda, are heavily rooted in Paktika and neighboring Paktia and Khost provinces.
One of the captured leaders provided insurgent fighters with funding, weapons, supplies and hideouts, and the other coordinated attacks against Afghan forces, the coalition said.