NATO soldiers killed in Afghanistan attacks

Four soldiers belonging to the U.S.-led NATO force in Afghanistan were killed by an improvised explosive device during an operation Sunday, while a fifth was shot dead Saturday by a contracted security guard in the country's south.

The Taliban have moved to recover ground in Afghanistan as foreign bases close as part of a decision to wind down operations and withdraw most troops by the end of 2014. The attacks highlight growing instability throughout the country ahead of the pullout. 

The nationalities of the four soldiers killed on Sunday were not released, but a military official speaking on condition of anonymity confirmed to the Associated Press that all were Americans.

Details surrounding the NATO soldier killed on Saturday remain murky. Officials have yet to release the nationalities of the soldier or guard.

If the guard turns out to be a contracted Afghan, it would be the ninth “insider attack” this year, bringing the toll of foreign personnel killed by their local counterparts to 14.

So-called "insider attacks" on foreign soldiers by Afghan allies escalated last year, prompting coalition troops to heighten security measures and reduce interaction between foreign and Afghan forces. The move helped stem the number of incidents this year, but also eroded trust between foreign-service members and their Afghan allies.

Earlier Saturday, at least five Afghan civilians, including three children, were reportedly killed in a NATO airstrike in eastern Afghanistan after having gone out hunting for birds with air guns. "They were targeted and killed by a foreign forces airstrike," Hazrat Hussain Mashreqiwal, a provincial police spokesman, said.

NATO officials contested Mashreqiwal's statement. Lt. Col. Will Griffin told Agence France-Presse that "while we are still assessing the situation, our initial reports indicate there were no civilian casualties."

More than 1,000 Afghan civilians have been killed and around 2,000 others injured in the first half of 2013, according to a U.N. report. The numbers represent a 23 percent increase from the same period last year, and are the cause of heightened tensions between NATO troops and the Afghan government.

Al Jazeera and wire services