N Korea 'combat posture to hit US'

North Korea says it has ordered artillery and rocket units into "combat posture" to prepare to target US bases in Hawaii, Guam and the US mainland.

The announcement, carried by KCNA news agency, follows days of strong rhetoric from Pyongyang.

It came as South Korea marked the third anniversary of the sinking of the Cheonan warship, which left 46 sailors dead.

Lucy Williamson reports from Seoul.

Footage from N Korea state TV