The rockets were fired towards the Yellow Sea from the west of the Korean peninsula on Tuesday, an official from Seoul's Joint Chiefs of Staff told AFP.

Yonhap News Agency reported, citing military officials, that the firing was part of the North Korean military's regular winter-time exercises.

Pyongyang has not commented on the launch, which came the same day that it began a major meeting of top officials.

That meeting, led by leader Kim Jong Un, will discuss key policy issues as well as plans for an upcoming Workers' Party congress -- North Korea's first in five years.

On the first day officials approved "five agenda items" for discussion this week, including a review of the work of the party's Central Inspection Commission, responsible for rooting out corruption, state media reported.

Lim Eul-chul, a professor at the Institute for Far Eastern Studies at Kyungnam University, told AFP the meeting would likely focus on the economy.

"There is a strong possibility that Kim Jong Un will present policies aimed at achieving breakthrough economic development over the next five years," he said.

The launch also comes a week after South Korea's dovish President Lee Jae Myung said he felt an apology was due to the North over his predecessor's alleged order to send drones and propaganda leaflets across the border.

Pyongyang has not responded to the overture from Lee, who has sought to mend fractured ties with the North.

North Korea last fired multiple artillery rockets last month, just hours before US Defense Secretary Pete Hegseth visited the border separating it from the South.

It also fired similar weapons minutes before President Lee held talks with Chinese leader Xi Jinping in November, Seoul said.