Taliban militants attacked two bases of the International Security Assistance Force (ISAF) in eastern Afghanistan in predawn raids on Saturday.
Militants attacked the bases in Khost province with indirect and small arms fire, a Nato statement said, adding that ISAF troops repelled the attackers and killed at least 10 insurgents, capturing several more.
The Taliban claimed responsibility for the attacks on the Forward Operating Base Salerno and nearby Camp Chapman, where seven agents of the US Central Intelligence Agency (CIA) had been killed by a suicide bomber in December.
Taliban spokesman Zabiullah Mujahid said that 20 suicide attackers targeted a US intelligence base in Khost city while eight others attacked a second Nato base in the city.
He also said that dozens other insurgents attacked police checkpoints and battle was ongoing. He claimed 18 foreign soldiers were killed in these attacks.
"Two groups of insurgents with AK-47 (rifles) and rockets attacked foreign forces camps and police checkpoints in Khost city," provincial police chief, Mr Abdul Hakim Ishaqzia, told DPA.
Forty-eight Taliban fighters were involved the attacks, he said, adding that the militants have evaded capture. A search operation was launched by Nato and police, he added.