KABUL, Afghanistan -- Two Afghan soldiers tried to gun down a group of NATO troops outside a military base in eastern Afghanistan on Thursday, officials said. No international forces were killed, but one of the attackers was killed as NATO forces shot back.

It was the second apparent attack by Afghan forces on their international counterparts this week. On Tuesday, two gunmen wearing Afghan army uniforms killed a U.S. soldier and wounded two others in Paktia province, also in the east.

Taliban spokesman Zabiullah Mujahid claimed responsibility for Thursday's attack but only mentioned one assailant. He said that man was a soldier who had contact with the Taliban before launching the attack.

This year has seen a growing number of the so-called "green-on-blue" attacks in which Afghan soldiers or police have turned on their international colleagues. Some of the attackers have been insurgent infiltrators, while others have been trying to settle personal vendettas.

The Thursday morning attack took place outside a "co-ordinationcentre" for Afghan and international forces in Laghman province, said German Lt. Col. Hagen Messer, a spokesman for NATO forces in Afghanistan. He said no NATO troops were killed but declined to say if any were wounded.

The two men attempted to ambush a group of international soldiers outside the base but were quickly repelled, said a spokesman for the 201 Afghan army corps, Maj. Noman Hatefi. He said the second attacker was arrested but did not say whether by international or Afghan forces. The Laghman governor's office said in a statement that the second Afghan soldier was wounded by the return fire.

So far this year, 27 coalition service members have been killed in 20 green-on-blue attacks, according to an Associated Press tally. That compares with 11 fatal attacks and 20 deaths the previous year. In 2007 and 2008 there were a combined total of four attacks and four deaths.

NATO's goal is to turn over security responsibility to local forces in Afghanistan by the end of 2014.