A powerful explosion has rocked a US military base in eastern Afghanistan and reportedly killed at least 27 American soldiers and left dozens wounded. Taliban spokesman Zabiullah Mujahid claimed responsibility for the deadly attack, saying the huge explosion left at least 27 American troops killed and 34 others wounded, a Press TV correspondent reported. The incident occurred early Thursday when a truck bomb went off inside the US military base in Gardez city, the capital of Afghanistan's Paktia province. According to the Taliban spokesman, the truck contained hundreds of kilos of explosives. Witnesses say the explosion was very powerful and a US helicopter was also destroyed in the blast. American forces in Afghanistan have been experiencing their deadliest days since the beginning of August.