N Korea 'warns of live firing drill'

It would be the second time within a month that Pyongyang had carried out such exercises, BBC News reports.

South Korea's defence ministry said it had been notified that the drills would take place near two sets of islands to the west of the Korean peninsula.

A South Korean spokesman said its military was "fully prepared".

A similar North Korean exercise at the end of March resulted in the two sides exchanging hundreds of rounds of artillery fire.

This latest warning from North Korea comes as satellite images suggested the North was preparing to carry out a fourth atomic bomb test.

It also follows President Barack Obama's visit to South Korea last week, which was strongly opposed by North Korea.

Washington has led calls for Pyongyang to abandon its nuclear weapons programme.