The Democratic People's Republic of Korea (DPRK) fired Tuesday scores of artillery onto a South Korean island and also into waters off the west coast of the Korean peninsula near a tense maritime border, Seoul's Joint Chiefs of Staff (JCS) said.

Reportedly fired at 2:34 p.m. local time, some shells landed on South Korea's Yeonpyeong Island and local residents are currently moving to shelters. Four soldiers have been injured with one of them in a critical condition, according to media reports.

South Korea fired back in response, and the military is now put on a heightened alert, officials said. It also deployed fighter jets to the west sea, according to Seoul's Yonhap News Agency.

"We urge North Korea to immediately stop provocation and we will sternly deal with it in case of further provocation," Yonhap quoted South Korean defense minister Kim Tae-young as telling lawmakers.

The exchanges of fire come when South Korea was engaged in massive annual military exercises involving some 70,000 troops, launched Monday and scheduled to last through Nov. 30.

The incident also comes shortly after Pyongyang's disclosure of a new and sophisticated facility to enrich uranium, which sparked new concerns here over potential nuclear threats.

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新华网首尔11月23日电（记者姬新龙）韩国国防部新闻办公室23日下午向新华社记者证实，韩国西部延坪岛附近当天14时30分许遭到来自朝鲜方面的炮击，韩国军队进行了回击。

朝鲜方面目前尚未对此做出表态。

韩国国防部官员没有详细透露炮击的数量、遭到炮击后的情况以及韩国军队回击的情况。

据韩国YTN电视台报道，延坪岛附近23日下午遭到朝鲜的数十发海岸炮炮击，数十座建筑和住宅受损或起火，韩国军方回击了数十发炮弹。

韩国联合通讯社的报道说，数发炮弹落到了延坪岛上。

延坪岛靠近韩朝存在争议的“北方界线”附近，岛上有不少居民。

目前人员伤亡情况尚不清楚。军方说，与人员伤害相关的情况仍在确认之中。