Afghan officials say a suicide car bomber and other suspected insurgents attacked a NATO base outside the eastern city of Khost on Friday.

A NATO spokesman tells VOA that 14 suspected insurgents were killed in clashes at the base before Afghan and coalition forces repelled the attackers.

The French news agency says seven Afghan civilians were killed. As many as 30 people were injured .

The Taliban claimed responsibility for the attack.

The ongoing violence in Afghanistan has raised concerns about the ability of Afghan forces to handle security after NATO pulls combat troops out of the country by the end of 2014.

On Thursday, the United Nations Assistance Mission in Afghanistan said civilian casualties from the Afghan conflict remain at “unacceptably high levels.”

UNAMA said it documented more than 3,000 conflict-related civilian deaths last year, three-quarters linked to violence by anti-government forces.