North Korea has fired artillery shells into waters near its sea border with South Korea, Seoul's military said, a day after the country test-launched two ballistic missiles in the latest of a series of weapon tests.

The shells fired on Monday from sites near the heavily fortified land border landed north of the maritime border. South Korea has not returned fire, an officer at Seoul's Joint Chiefs of Staff said, adding that the North Korean fire was continuing.

South Korea's Yonhap news agency said the North fired 100 shells, presumed to be from multiple rocket launch systems.

The news agency cited an unidentified military official.

The eastern sea border is clearly marked compared with the Koreas' disputed western sea boundary, the scene of several bloody maritime skirmishes between the two Koreas in recent years.

The Koreas exchanged artillery fire twice earlier this year near the western sea boundary.

Over the past few weeks, North Korea has been conducting an unusually large number of missile and rocket tests, including two ballistic missile launches late on Sunday, though it has also proposed a set of measures it said will lower tension between the Koreas.

Analysts said the conflicting moves indicate North Korea will keep trying to bolster its defense regardless of its recent push to lower tension unless Seoul and Washington make major concessions, such as scaling down regular military drills it calls an invasion rehearsal.

Earlier on Monday, South Korea said the North had agreed to hold talks at a border village on Thursday to discuss the North's participation in the upcoming Asian Games in the South.

Source: Agencies