SEOUL - North Korea fired artillery shells Monday into waters near the disputed border in the Yellow Sea amid high tensions with South Korea, Seoul`s defence ministry said.

"A North Korean battery opened fire today in waters off the west coast," a spokesman told AFP, declining to give details.

Yonhap news agency said the North fired some 100 rounds shortly after the South ended a five-day naval exercise in the Yellow Sea. It said the shells landed in the sea on the North`s side of the line.

The exercise was a show of force after Seoul accused its neighbour of torpedoing a South Korean warship in March near the contested border.

The North, which denies staging the attack that killed 46 sailors, had warned of "strong physical retaliation" against the naval exercise which it described as a preparation for invasion.

The North`s seizure Sunday of a South Korean fishing boat in the Sea of Japan (East Sea) has further inflamed tensions.

BDST: 1622 HRS, August 09, 2010