A roadside bomb in southern Afghanistan killed five American soldiers Saturday. The International Security Assistance Force said an improvised explosive device was used in the attack, according to NPR.

U.S. Army soldiers in the Kandahar province of Afghanistan. (lafrancevi/Flickr)

According to Javeed Faisal, a spokesman for the governor of Kandahar province, "a coalition patrol hit the roadside bomb in Maiwand district of the province, the spiritual birthplace of the Taliban."

Two other NATO troops were also killed in western Afghanistan by an Afghan National Army soldier. These types of attacks are known as "insider attacks" and have eroded the relationship between Afghan and foreign forces.

According to AFP, "NATO-led soldiers are fighting alongside Afghan colleagues to thwart Taliban militants, but more than 60 foreign soldiers were killed in 2012 in insider attacks that have bred fierce mistrust between allies."

The Washington Post reported the two soldiers were American, according to two U.S. officials who spoke anonymously ahead of the official announcement of the soldiers' nationalities.

READ MORE: Afghanistan's Bloodiest Day In Eight Months

The attacks come one week after the Taliban launched its annual spring offensive. According to AFP, this is a crucial period for Afghanistan as its security forces take the lead in offensives against insurgents who are fighting to topple the US-backed government.

The Washington Post reported:

"The renewed violence came as Afghan President Hamid Karzai acknowledged at a news conference that regular payments his government has received from the CIA for more than a decade would continue. Karzai also said that talks on a U.S.-Afghan bilateral security agreement to govern future American military presence in the country had been delayed because of conditions the Afghans were placing on the deal."

READ MORE: CIA Gives Cash To Afghanistan's Karzai

According to Reuters, this week has been one of the "bloodiest weeks" for international forces in Afghanistan this year. "Nineteen U.S. personnel have been killed in the last week in three air crashes and Saturday's bombing. Three British soldiers were also killed on Tuesday by a roadside bomb in the southern province of Helmand."

NPR reports "the United States and its allies are in the process of handing security responsibilities over to Afghanistan's own forces, culminating in the withdrawal of most foreign troops by the end of 2014."

All NATO combat missions will finish by the end of next year.

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