KHOST, (Reuters) – A suicide bomber killed two foreign troops and two Afghan civilians in a bazaar outside a NATO base in southeastern Afghanistan on Sunday, and wounded nearly 20 others, NATO and Afghan officials said.

The Taliban claimed responsibility for the blast in Gardez district of Paktia province, near the Pakistan border.

Major S. Justin Platt, spokesman for the NATO-led International Security Assistance Force (ISAF) in Paktia confirmed there had been several casualties.

“There were two ISAF soldiers killed and six wounded,” Platt told Reuters by phone from the region.

ISAF officials in Kabul confirmed it was a suicide blast.

The explosion happened as a group of foreign and Afghan soldiers were shopping, a military source in Kabul told Reuters, adding at least four Afghan troops were also wounded.

“Two (Afghan) shop keepers were killed. Eighteen other people … were wounded,” Rohullah Samoon, a spokesman for the provincial governor, said by phone.

The Taliban spokesman said 19 local and foreign soldiers were killed in the attack, although the group often inflates casualties among Afghan and foreign troops when reporting attacks.

This year has been the bloodiest since the 2001 ousting of the Taliban government, with violence rising and spreading to previously fairly peaceful areas of Afghanistan, despite the presence of some 150,000 foreign troops.