16 March 2013 Last updated at 10:42 ET

A North Korean propaganda website has warned of strikes against Southern islands and advised residents to leave.

The Uriminzokkiri website, linked to the regime, mentioned targets including Yeonpyeong island, which was attacked by Northern forces in 2010.

Pyongyang has made a series of threats since its last nuclear test in February prompted the UN to tighten sanctions.

The US said on Friday it would refocus missile defences to its west coast to counter the North's threats.

Defence Secretary Chuck Hagel said 14 more batteries would be placed in Alaska by 2017, adding to 30 already in place along the coast.

On 12 February the North tested a nuclear device, which is believed to be its third such test.

The UN Security Council condemned the move and tightened sanctions on the regime.

Before and after the UN announcement, Pyongyang promised reprisals for the sanctions, including a threat to launch a pre-emptive nuclear strike against the US.

North Korean media has also been vitriolic against the South.

Read more from the original source:

N Korea tells South to leave islands