Seoul - North Korea on Saturday fired a salvo of seven missiles off its east coast, in an act of defiance apparently timed for July 4, the United States' Independence Day.

The provocative timing looks to be Pyongyang's way of telling Washington that it will not be cowed by recent US moves to get tough over its nuclear weapons programme.

In a span of about seven hours yesterday, Pyongyang launched seven missiles into the Sea of Japan, known in South Korea as the East Sea.

It was the biggest barrage of ballistic weaponry since the North fired a long-range Taepodong-2 and six smaller missiles in 2006, coinciding too with Independence Day in the US.

Both South Korea and Japan swiftly condemned the action as provocative. Russia and China on Saturday urged all parties to show restraint and to return to the negotiating table.

South Korea's Yonhap news agency, citing intelligence sources, said the first three appeared to be Rodong missiles, while the rest were an upgraded version of Scud-C missiles.

Scud-C missiles have a range of up to 500km, which could hit most of South Korea. The Rodong has a range of up to 1,300km, putting most parts of Japan within striking distance.

Defence analysts say the North has about 600 Scuds and another 200 Rodong-1 missiles.

The test-firing was in defiance of United Nations resolutions, which ban North Korea from firing Scuds, medium-range missiles or long-range missiles.

Professor Kim Yong-Hyun of Seoul's Dongguk University said the successive missile volleys were 'a thinly veiled warning to the United States and the international community that it may launch long-range missiles the next time'. -- AP, Reuters, AFP, New York Times

Read the full story in The Sunday Times.