(CNN) -- Four soldiers -- three of them part of the U.S.-led coalition, one of them NATO -- were killed Sunday in separate combat incidents in eastern Afghanistan, according to coalition and NATO statements.
The three coalition soldiers died Sunday after sustaining wounds in an explosion during fighting in Nangarhar province, along the border with Pakistan, the Coalition Press Information Center said.
An interpreter also was killed in the blast, the center reported.
In addition, "one coalition forces service member was wounded in the strike and was transported to a nearby coalition forces medical center for treatment," according to a news release.
The soldiers' names and nationalities were not released.
In southern Afghanistan, a NATO soldier was killed during an attack Sunday, NATO's International Security Assistance Force said.
Several other NATO soldiers were wounded, as well as an Afghan National Army soldier, ISAF added.
The statement did not provide the location of the attack or the nationality of the soldier killed.
"Our thoughts at this very difficult time are with the friends, family and colleagues of those who have been killed and injured," ISAF spokeswoman Lt. Col. Bridget Rose said.
U.S. and NATO troops have been battling a resurgent Taliban in southern Afghanistan for months.
Last week, Taliban militants attacked the same coalition outpost, Firebase Anaconda, in Uruzgan province three times in five days.
Several Taliban militants were killed in two attacks on the base Saturday, and about 25 insurgents were killed by U.S. troops, backed by airstrikes, Tuesday when the insurgents ambushed the base from three directions, the coalition reported.