North Korea accuses US of 'hack attack'

North Korea has accused the US and its allies of attacks on its internet servers, amid tension on the peninsula.

KCNA news agency said the "intensive and persistent" attacks coincided with US-South Korea military drills.

Official sites such as KCNA, Air Koryo and Rodong Sinmun, the party newspaper, are reported to have been inaccessible on some occasions in recent days.

Tension has escalated in the wake of North Korea's third nuclear test last month.

Lucy Williamson gives more detail on the reaction to the North Korean accusations.