Afghan police say a suicide bomber blew himself up Sunday outside a local police headquarter in eastern Afghanistan, killing two policemen and wounding two civilians.

The attack took place in Yahya Khel district in Paktika province near the Pakistani border.

Also Sunday, NATO said two of its service members died in eastern Afghanistan from separate bomb blasts.

A NATO statement also said combined Afghan and coalition forces killed 12 insurgents and captured at least 12 others during security operations across the country Sunday. The statement said that among the captured were several Taliban leaders responsible for conducting ambushes and roadside bomb attacks against Afghan forces.

In the country's central Ghor province, a German tourist and his Afghan companion were killed and two other Afghans were wounded by armed men on motorcycles. Saturday's attack came weeks after unknown assailants killed two German tourists hiking in the mountains near the capital, Kabul.

In a separate development, Afghan President Hamid Karzai has appointed a team to investigate the assassination of former President Burhanuddin Rabbani, who headed the nation's peace council and was leading efforts to find a political solution to the 10-year war with the Taliban. He was killed last week in a suicide attack at his home in Kabul.