North Korea test-fired several short-range missiles on Friday, South Korea said, in what analysts saw as a show of anger at Washington and the new conservative government in Seoul.
The launch comes a day after the North expelled South Korean officials from a joint industrial complex north of the border after Seoul told its prickly neighbour to clean up its human rights and stop dragging its feet in nuclear disarmament talks.
A South Korean presidential spokesman told a news briefing that the North had fired short-range missiles as a part of a military exercise. Local news reports said three were launched into the sea off the west coast.
"We believe the North does not want a deterioration of relations between the South and the North," spokesman Lee Dong-kwan told reporters.
New South Korean President Lee Myung-bak has said he wants to end the free ride given to North Korea under 10 years of left-leaning presidents who gave billions in aid while asking for little in return, seeing it as the price to pay for stability.
Lee's government has said it is ready to invest heavily in the impoverished state, provided the North meets conditions such as taking apart its nuclear arms programme or returning the more than 1,000 South Koreans it kidnapped or kept in the country after the 1950-53 Korean War.
Pyongyang was basically sending two messages with its missile launch, Keio University Korea expert Masao Okonogi said in Tokyo.
One was aimed at the United States after talks in Geneva, showing the North's dissatisfaction with Washington's pressure to come clean on uranium enrichment and ties with Syria, he said. The other was a riposte to the Lee government's shift in stance.
