UNDATED (CBS) -- At least two U.S. servicemen are dead after an Afghan police officer opened fire. It's the latest in a string of attacks in Afghanistan where insurgents appear to be infiltrating security forces.
Lance Corporal Greg Buckley Junior will be buried Saturday in his hometown of Oceanside, New York.
Someone the young marine thought was an ally shot him in Afghanistan last week. The 21-year-old was sharing a meal with an Afghan police officer when the officer pulled out his weapon and started firing - killing Buckley and two other marines. And it's happened again.
On Friday in the province of Farah an Afghan police recruit shot and killed two U.S. servicemen just moments after receiving his new weapon. In another part of the country an Afghan soldier opened fire on NATO troops wounding two of them.
NATO leaders say coalition forces killed both attackers. NATO spokesman Brig. Gen. Gunter Katz says, "The investigation is still ongoing and we have no findings yet, in terms of what the reason for this insider-threat-incident was."
These types of attacks are on rise. This year members of Afghan security forces have killed at least 36 coalition troops.
NATO says it will continue to train Afghan forces to take over the country's security. Most U.S. and allied troops are scheduled to leave in 2014.
The Taliban's supreme leader claims insurgents are cleverly infiltrating Afghan security with the purpose of killing coalition troops.
NATO says insider threats are relatively small in number. But at Buckley's wake Thursday his father said his son was concerned about this kind of attack and feared for his life. Buckley's father Greg Buckley says, "At the end of the day what happens, my son trains someone to kill him."
Coalition troops are currently training 340,000 Afghan forces. The international coalition says Afghan forces are already starting to assume security in many area of the country.