GARDEZ, Afghanistan (Reuters) -- A suicide bomber killed 45 people at a volleyball match in Afghanistan Sunday, a provincial official said, as foreign troops withdraw from the country after more than a decade of fighting. Mukhles Afghan, a representative of the governor of Paktika province, said at least 50 more were wounded in the attack in Yahya Khel district, where residents had gathered to watch a tournament final. He said most of the casualties were civilians.

Nobody immediately claimed responsibility for the attack, which saw the bomber walk into the crowd of spectators and detonate his explosive vest, Afghan said. “Sadly we have 45 people killed and around 50 others wounded in this suicide attack,” he said.

Casualties were high because the crowd was so dense: Many people had come from nearby districts to cheer on their team. No other details were immediately available because of the remoteness of the location.

The Taliban and other jihadist militants have unleashed waves of suicide attacks and assassinations in Afghanistan this year, as foreign forces pull out after 13 years of war. About 12,000 international troops will remain in Afghanistan next year to train and support the country’s security forces.

Paktika was the site of one of this year’s deadliest attacks on civilians in July, when 89 people were killed by a bomb in a crowded market. The province has an active Afghan Taliban insurgent presence and lies along the porous border with Pakistan’s lawless North Waziristan region, used as a base by both the Haqqani militant network and the Pakistani branch of the Taliban.

The Pakistani army for months has been waging an offensive against militants in North Waziristan, driving many refugees and militant fighters across the border into Afghanistan.

This year has been one of the bloodiest years of the war for Afghan civilians, according to the United Nations, which recorded nearly 5,000 deaths and injuries of civilians in the first half of 2014. About three-quarters of those were blamed on the Taliban and its allies.

(Reporting by Samiullah Paiwand; Additional reporting by Hamid Shalizi; Writing by Kay Johnson; Editing by Maria Golovnina and Andrew Roche)