(Updates death toll, adds details)
GARDEZ, Afghanistan, June 3 (Reuters) - A suicide bomber targeting a U.S. military convoy detonated a motorbike packed with explosives outside a boys' high school in eastern Afghanistan on Monday, killing at least six students, two U.S. soldiers and a policeman, officials said.
About 20 people were wounded in the attack near the office of the governor of Paktia province. Most were schoolchildren, but they also included five U.S. soldiers, local officials said.
The bomber struck at about 11.30 a.m. next to Samkani Boys High School as the convoy of U.S. soldiers and members of the Afghan Local Police (ALP) was nearby.
"There were American soldiers and ALP close to the high school when the bomber detonated his explosives," Paktia police chief General Zalmai Oriakhil told Reuters.
He said at least 10 students had died, along with one ALP officer. About 20 people were wounded, he said.
A statement by the the NATO-led International Security Assistance Force (ISAF) said two ISAF service members and six Afghan civilians had been killed. As per usual practice, it did not identify the nationality of the ISAF soldiers.
A Reuters witness who visited the hospital where the casualties were taken said most of the injured were schoolchildren aged under 12.
Concerns are mounting over how the 352,000-strong Afghan security forces will cope with an intensifying insurgency once most foreign troops leave by the end of next year.
The U.S.-led force says the insurgency is responsible for about 86 per cent of all civilian casualties - or about 1,500 people - across the country this year.
Also on Monday, a roadside bomb struck a truck and killed seven Afghans, including five women in Mehtarlam, the capital of eastern Laghman province, the interior ministry said.
At the weekend, four Americans - three soldiers and an ISAF contractor - were killed in three incidents in the east and south of the country. (Reporting By Samihullah Paiwand; Writing by Dylan Welch; Editing by Ron Popeski)