Afghan and coalition soldiers fought off assaults on two military bases Saturday and killed more than 20 insurgents, NATO's International Security Assistance Force said.
The fighting occurred in Khost province, a volatile province on Afghanistan's rugged border with Pakistan.
Insurgents clad in U.S. military uniforms and wielding rocket-propelled grenades and small arms "simultaneously launched attacks" against Forward Operating Base Salerno and Forward Operation Base Chapman.
Chapman is the same place where a suicide bomber killed seven CIA officers on December 30.
Troops killed about 15 insurgents at Salerno and six at Chapman. Five insurgent fighters were captured and were in ISAF custody.
A Haqqani network operative who helps carry out bombings and two other insurgents died in an airstrike while fleeing Salerno in a vehicle. Two insurgents who got into Salerno were killed by soldiers. The Haqqani network is a militant group with ties to al Qaeda.
"We are tightening our grip on the insurgents and as a result they are attempting anything and everything as a last ditch effort," said U.S. Army Col. Rafael Torres, ISAF spokesman. "The insurgents gave their best effort and came up short."
Afghan police and ISAF members seized a car bomb and a vehicle carrying ammunition. Forces also seized suicide vests, rifles and unexploded munitions.
Four ISAF soldiers were injured, and three have returned to duty. The fourth was set to return to duty soon. No base facilities were damaged.
CNN's Joe Sterling contributed to this report