Kabul, Afghanistan (CNN) -- Two international service members were killed in a shootout at an Afghan police compound, NATO's International Security Assistance Force said Friday.

The two who died were part of a mentoring team that was preparing to eat lunch with Afghan police at a compound in southern Helmand province Thursday. A uniformed policeman opened fire at the ISAF troops. The gunman was seriously injured in the incident, ISAF said.

"While this is a serious incident, the actions of this individual do not reflect the overall actions of our Afghan partners," said U.S. Marine Corps Maj. Gen. James B. Laster of ISAF. "We remain committed to our partners and to our mission here."

Late last month, eight U.S. troops and a U.S. civilian contractor were killed in a shooting at an Afghan air force compound in Kabul. ISAF said the gunman was an Afghan military pilot. The Taliban, however, claimed responsibility for the attack and said it had been working with the shooter for some time -- an assertion that ISAF denied.