KABUL, Afghanistan - The death toll in Afghanistan's deadliest insurgent attack this year has risen to at least 50, with 63 wounded, many of them children, officials said on Monday, as NATO confirmed that two of its service members were killed in an insurgent attack.

The nationality of the NATO soldiers could not be confirmed, according to protocol. The deaths bring the total for this month of foreign service members killed in Afghanistan to three. The total number killed this year is 63, 46 of them Americans.

NATO provided no further details, but the spokesman for Kabul's police chief, Hashmat Stanekzai, said a bomb attached to a bicycle detonated near a foreign military convoy in the eastern part of the capital Kabul just before 9 a.m. One Afghan civilian was wounded, he said.

The attack, one of a rising number in Kabul in recent months, came as officials confirmed that a suicide bombing on Sunday in Paktika province, in the east of the country bordering Pakistan, had targeted local police.

The attack took place during the final of an inter-district volleyball tournament that had attracted a huge crowd. The spokesman for the provincial governor, Mokhlis Afghan, said that 42 people were killed immediately.

Seddiq Sediqqi, the spokesman for the Interior Ministry, said the dead included 10 members of a local police force, including a police commander. He said that 53 wounded had been transported overnight by helicopters for treatment in Kabul. They included 17 children aged between 8 and 14 years old.

Witnesses said the bomber approached the police commander and shook his hand before shouting "Allahu Akbar" (God is greatest) and detonating explosives carried on his body.

Abdullah, a member of the Afghan Local Police in Yahyakhail district, where the attack happened, said from his hospital bed in Kabul: "I heard the bomber shout `Allahu Akbar' a split second before the explosion."