A roadside bomb killed a NATO soldier and wounded four others in southern Afghanistan, while a Taliban ambush left eight Afghan security personnel dead, officials said.
The NATO soldiers were patrolling in the country's volatile south Sunday when an explosion ripped through their vehicle, NATO said in a statement.
"They were immediately evacuated for medical care ... (but) sadly one died of wounds inflicted by the explosion," it said.
NATO did not identify the nationalities of the dead and wounded soldiers, or the exact location of the blast. Militants regularly attack foreign and Afghan troops with roadside bombs in that part of the country.
In central Wardak province, meanwhile, Taliban militants fired rocket-propelled grenades from their vehicles at a convoy led by private security guards on Saturday, killing six guards and two police officers, said Wardak police chief Gen. Zafaruddin, who goes by one name.
The security contractors were guarding equipment on the main highway linking the capital with the country's south, when militants opened fire near Maydon Shahr, about 30 kilometer (20 mile) southwest of Kabul, Zafaruddin said.
This year has been Afghanistan's most violent since the 2001 U.S.-led invasion drove the Taliban from power. More than 6,300 people, mostly militants, have been killed in insurgency-related violence, according to an Associated Press count.
Meanwhile, the U.N.'s top representative here, Tom Koenigs, said he was "particularly concerned" that an Afghan consultant who worked for the U.N. remains jailed after he accompanied officials from the U.N. and European Union, allegedly to a meeting with Taliban commanders in Helmand province.
The government asked the two officials to leave the country last week, and detained the Afghan consultant.
"We've made it clear to the Afghan government that we want to see him released as soon as possible, because even the government has publicly stated that no U.N. staff member was involved in any secret talks," said Aleem Siddique, a spokesman for the U.N. mission.
Koenigs said "underlying assumptions" from some elements within the Afghan government were misunderstandings. That was an apparent reference to allegations that the two officials met with and may have handed money over to Taliban leaders.
He said the U.N. was not involved in any intelligence operations or paying money to any insurgents.
Koenigs, the head of the U.N. Assistance Mission to Afghanistan for the last two years, left his post on Sunday. Bo Asplund, a Swedish national, is now the officer in charge until a permanent head is named.
Paddy Ashdown, a former leader of Britain's opposition Liberal Democrats who served previously as Bosnia-Herzegovina's international administrator, is a leading candidate to replace Koenigs.