The launches followed Seoul's expression of regret on Monday over civilian drone incursions into the North in January, with South Korean President Lee Jae Myung calling it "irresponsible" and noting that government officials had been involved in the operation.

The missile launches are seen as North Korea's latest rebuff of South Korea's peace overtures, according to analysts.

Seoul's military initially said on Wednesday morning it had detected "an unidentified projectile launched from the Pyongyang area on Tuesday."

Around an hour later the military said it also detected "multiple unidentified ballistic missiles fired from the Wonsan area of North Korea towards the East Sea" on Wednesday morning, referring to the body of water also known as the Sea of Japan.

The missiles flew around 240 kilometres (149 miles), they added.

South Korean President Lee has sought to repair ties with North Korea since taking office last year, criticising his predecessor for allegedly sending drones to scatter propaganda over Pyongyang.

Following Lee's expression of regret over the drones on Monday, the powerful sister of North Korean leader Kim Jong Un said Lee's regret was "wise behaviour".

"Our government appreciated it as very fortunate and wise behaviour for its own sake," Kim Yo Jong said on Monday.

But on Tuesday, a senior North Korean foreign ministry official described the South as "the enemy state most hostile to the DPRK", using the initials of the North's official name, reiterating a label used by leader Kim previously.

Referring to South Korean media reports that cast a positive light on Kim Yo Jong's comments about Lee, the official said such a stance was "nonsense".

"Regarding the rapid response from our government as an 'exceptional friendly response'... this will also be recorded as world-startling fools' 'hope-filled dream reading'", Jang Kum-chol, first vice-minister of Pyongyang's foreign ministry, said in an English statement carried by the official Korean Central News Agency.

The launches are Pyongyang's message to Seoul that its anti?South stance remains firm despite Seoul's repeated overtures, said Lim Eul?chul, an expert on North Korea at Kyungnam University.

"The consecutive firings and recent statements underscore the North's determination to ignore attempts by the South at improving inter?Korean ties," he said.

- Irreversible course -

Lee's expression of regret came after North Korean leader Kim Jong Un labeled Seoul as the "most hostile state" in a policy address in March in which he vowed to "thoroughly reject and disregard it".

North Korea's leader also reaffirmed his commitment to maintaining the country's nuclear arsenal, describing it as an "irreversible course".

Former South Korean president Yoon Suk Yeol is standing trial over charges that his administration sent drones into the North to provoke a backlash and create a pretext for declaring military rule.

During Yoon's presidency, relations between Seoul and Pyongyang hit rock bottom, with the North sending balloons filled with garbage, including animal manure, in response to propaganda leaflets sent northward by South Korea-based activists, many of them North Korean defectors.

The two Koreas technically remain at war, as the 1950-53 conflict ended in an armistice rather than a peace treaty, and both enforce mandatory military service for men.