North Korea fires at least one ballistic missile: Seoul military

North Korea fired at least one ballistic missile, Seoul's military said Saturday after it blamed the North for an explosion in the Demilitarised Zone that wounded three South Korean soldiers.

Seoul's military demanded an official apology for the landmine blast, but Pyongyang has denied being responsible, calling South Korea "despicable".

Seoul and the US-led United Nations Command found that last month's explosion inside the DMZ, the heavily mined buffer dividing the two Koreas since their 1953 armistice, was caused by North Korean mines laid on the South side of the border.

Early Saturday, "our military detected a ballistic missile launched from the Wonsan area of North Korea toward the East Sea," Seoul's Joint Chiefs of Staff said, referring to the body of water also known as the Sea of Japan.

"South Korea, the US, and Japan are maintaining a robust defense posture through close information sharing regarding North Korean ballistic missiles," it added.

South Korea's dovish President Lee Jae Myung had urged Pyongyang on Thursday to return to dialogue, despite his military demanding an apology a day earlier.

Pyongyang's military has laid mines and built anti-tank barriers along the frontier as part of efforts to permanently seal it off, since Kim Jong Un designated South Korea his country's "principal enemy" in 2024.

The mines responsible for last month's blast were believed to have been laid as part of Pyongyang's border fortification work, according to South Korea's defence minister Kang Shin-chul.

Unification Minister Chung Dong-young proposed to Pyongyang on Friday talks to address issues along the border.

Kim Yo Jong, the powerful sister of North Korea's leader, called Seoul "despicable" later Friday and once again denied Pyongyang was behind the blasts.

She also ridiculed Lee's latest overture, calling it "the climax of the farce that everyone should watch".

- 'Wild dream' -

In a separate report carried by Pyongyang's official Korean Central News Agency, she was quoted as saying it was "quite ridiculous" for South Korea to demand an apology.

She also dismissed Minister Chung's overture for talks as a "wild dream and unilateral jargon."

The flare-up comes at a sensitive time.

US President Donald Trump's recent overtures to Pyongyang have raised concerns that Seoul -- an ally of Washington -- could be sidelined in potential nuclear talks involving the North, which is backed by Russia as well as China.

South Korea's opposition People Power Party on Friday accused Lee of failing to criticise Pyongyang when warranted even as he takes a hard line on Ukraine for disclosing the confidential transfer of North Korean prisoners of war.

"South Korean soldiers have been injured, and far from receiving an apology, we have been mocked by North Korea," the opposition party said in a statement.

"We fail to see how selectively turning a blind eye to North Korea serves South Korea's dignity or the safety of its people."