North Korea has fired three short-range ballistic missiles toward its eastern waters in its latest weapons display.

It came a day after rival South Korea launched a solid-fuelled rocket as part of its efforts to build a space-based surveillance capability to better monitor the North.

Tensions between the rival Koreas rose earlier this week when South Korea accused North Korea of flying five drones across the rivals’ tense border for the first time in five years and responded by sending its own drones toward the North.

South Korea’s Joint Chiefs of Staff said in a statement it detected the three launches from an inland area south of Pyongyang, the North’s capital, on Saturday morning.

It said the three missiles travelled about 220 miles before landing in the waters between the Korean Peninsula and Japan. The estimated range suggests the missiles tested could target South Korea.

The Joint Chiefs of Staff called the launches “a grave provocation” that undermines international peace, adding that it closely monitors North Korean moves in coordination with the United States and maintains a readiness to “overwhelmingly” deter any provocation by Pyongyang.

The US Indo-Pacific Command said the launches highlight “the destabilising impact” of North Korea’s unlawful weapons programs and that the US commitments to the defence of South Korea and Japan “remain ironclad”.

Earlier on Saturday, Japan’s Defence Ministry also reported suspected ballistic missile firings by North Korea.

It was North Korea’s first missile launch in eight days and came five days after South Korea said it detected the North Korean drones, all presumed to be small surveillance drones, south of the border.

Before Saturday’s launches, North Korea had already test-fired more than 70 missiles this year. Many of them were nuclear-capable weapons designed to attack the US mainland and its allies South Korea and Japan.

This week, North Korea is under a major ruling party meeting in Pyongyang to review past policies and new policy goals for 2023.

It is highly unusual for North Korea to test-launch a missile when it holds a key meeting.

Later on Saturday, senior diplomats from South Korea, Japan and the United States jointly denounced the North’s launches after a phone call.

They agreed to reinforce their deterrence against North Korea and work together to achieve the North’s denuclearisation, according to the South Korean and Japanese foreign ministries.