Two NATO troops killed by Afghans

Two NATO soldiers were killed Thursday by a man believed to be an Afghan soldier and an Afghan civilian, the International Security Assistance Force (ISAF) said. 

The killings follow the shooting deaths of two U.S. officers in the Afghan Interior Ministry last week and will fuel further questions about the NATO mission to train and hand off security there to the Afghan National Security Force. 

The ISAF statement said the two Afghans, including one believed to be an Afghan National Army service member, turned their weapons on ISAF troops in southern Afghanistan.

ISAF did not release the nationality of the soldiers killed. 

Media reports from Afghanistan said the attack occurred just hours after some NATO personnel were allowed back into Afghan ministries in Kabul. They were removed following the Interior ministry shooting. 

Violence in Afghanistan has spiked after widespread protests over the accidental burning of Qurans at a U.S. airbase last month.

But violence involving supposedly friendly Afghans attacking NATO forces has been a continual issue in the country. A Pentagon report found there have been 42 such attacks from 2007 through January 2012.

Last week's ministry attacks prompted some Democrats to call for a quicker withdrawal from Afghanistan, while many Republicans argued it showed the United States needs to re-evaluate its plan to withdraw 23,000 surge troops this year.

NATO plans to hand over control of security to the Afghans by the end of 2014. The Obama administration said it was not changing its strategy after the Interior ministry shooting.

The administration has sought to ease tensions amid the continuing violence. Last month, President Obama offered a written apology to Afghan President Hamid Karzai over the burned Qurans. 

Republican lawmakers and the party’s presidential contenders have blasted Obama for the apology, saying it showed weakness.

In an interview with ABC News aired Wednesday, Obama defended the decision and the U.S. mission training Afghan security forces.

Obama said he believed Afghan troops "welcomed and benefited from the training and partnering that we're doing.”

But, he cautioned, "that doesn't mean there aren't going to some tragic incidents.”