North Korea has tested two short-range missiles, South Korean media report, as concern mounts in the region that a long-range test could be days away.

It test-fired other similar missiles earlier this week and has incurred fresh UN sanctions since holding a second underground nuclear test in May.

The latest missiles were fired from a base near Wonsan into the Sea of Japan, South Korea's defence ministry said.

They are believed to be Scuds with a range of 500km (312 miles).

A South Korean defence official said Saturday's tests were of greater concern than Thursday's, as the missiles had a much greater range.

The BBC's John Sudworth in Seoul says the launches are seen there as part of North Korean efforts to ratchet up the tension.

Japanese and South Korean media have reported that North Korea may be preparing to launch another long-range ballistic missile.

There are fears that North Korea is trying to produce nuclear warheads small enough to put on long-range missiles.

After six-nation talks aimed at curbing North Korea's nuclear ambitions broke down earlier this year, Pyongyang said it would "weaponise" its plutonium stocks and start enriching uranium for a light-water nuclear reactor.

On 12 June the UN Security Council approved a resolution allowing inspection of air, sea and land shipments in and out of North Korea suspected of carrying banned arms and weapons-related material.

The North has said it will treat any interception of its ships as a declaration of war.

http://news.bbc.co.uk/2/hi/asia-pacific/8134115.stm