Story highlights Afghanistan and Germany's foreign ministers meet in Kabul

2 American troops, 1 U.S. civilian are shot dead in eastern Afghanistan, ISAF says

1 Italian soldier dies in western Afghanistan, 3 are wounded, the coalition adds

NATO is winding down its military operations in Afghanistan

Three coalition troops and one civilian were killed Saturday in Afghanistan -- their deaths coming in two separate instances, one in the eastern part of the country and the other in the west -- NATO's International Security Assistance Force said.

Two American soldiers and an American civilian were shot dead by a gunman wearing an Afghan army uniform in the eastern Paktika province, according to an ISAF spokeswoman.

The shooter was killed and another was arrested, the coalition force said in a statement later Saturday. By then, the forward operating base where the attack occurred had been secured.

Separately, an Italian soldier was killed in western Afghanistan's Farah province by "hostile elements" targeting a convoy of military advisers, the Italian defense ministry said.

Three other Italian soldiers were wounded in that attack.

The incidents come days after 10 schoolchildren and two ISAF soldiers were killed in a bombing at a bazaar in eastern Paktika province. That province has been a hotbed for insurgent attacks, including a suicide bombing last October at a joint NATO-Afghan army base that wounded 45 Afghan soldiers.

U.S. President Barack Obama announced in February that some 34,000 U.S. troops in Afghanistan will return home within a year. That would cut the number of U.S. forces in the country by more than half.

This follows NATO's decision in May 2012 to accept Obama's exit strategy for the war-torn Asian nation that ends his alliance's combat operations in 2013 and withdraws all its military forces by the end of 2014.

Afghan Foreign Minister Zalmai Rassoul met Saturday with his German counterpart Guido Westerwelle at the presidential palace in Kabul.

Among other matters, the two discussed the security transition, the Afghan government's efforts to maintain peace and next year's elections in the country, according to a press release from the Afghan foreign ministry.