Seoul: South Korea's military said it would conduct a major ground and air live-fire exercise on Thursday near the North Korean border, as warships began a four-day exercise off the east coast on Wednesday.
Tensions remain high on the peninsula after the North threatened to hit back for a South Korean live-fire drill held on Monday on an island near the disputed sea border off the west coast. It later announced it would not retaliate.
A South Korean army spokesman said Thursday's drill on a range at Pocheon, 20 kilometres (12 miles) south of the border, would be the biggest held at the range. But he said similar drills had been held at Pocheon many times before.
The army said 800 soldiers would take part in the one-day drill. Six jet fighters, helicopters, tanks, K-9 self-propelled guns, anti-tank missiles and multiple rocket launchers would be used.
Nerves have been on edge since the North last month shelled Yeonpyeong island in the Yellow Sea, off the peninsula's west coast, in response to a South Korean artillery drill there.
The bombardment killed four people including civilians.
The South staged a repeat drill on Yeonpyeong on Monday but the North did not hit back despite earlier threats to do so.
"We will retaliate thoroughly if the North commits another provocative act like the shelling of Yeonpyeong," First Armoured Battalion commander Choo Eun-Sik told Yonhap news agency.
"Through this exercise (at Pocheon), we will demonstrate our solid military preparedness."
A separate four-day naval firing drill began Wednesday off the east coast, 100 kilometres south of the border with the North, involving six warships plus helicopters.
The military said it would practise responses to intrusions by North Korean submarines and patrol boats.