North Korea launched two ballistic missiles into the sea on Sunday, the south’s military said, the latest in a lightning wave of missile launches amid tensions over US-led military exercises in the region, Yonhap reported.

The South Korean military’s Joint Chiefs of Staff announced the launches – the seventh and eighth in two weeks – were coming from the south-east of the country, without giving further details.

“As we increase our surveillance and vigilance, our military maintains a full preparedness posture in close cooperation with the United States,” the Joint Chiefs of Staff said, according to Yonhap.

North Korea on Saturday defended its recent spate of missile tests as a legitimate counter to US military threats after days of joint military exercises between the South, Japan and the United States.

The Japanese Prime Minister’s office also confirmed at least one of the launches on Twitter on Sunday.

“North Korea has launched a suspected ballistic missile. More updates to come,” the office said.

Japanese Deputy Defense Minister Toshiro Ino said it was possible the missiles, which he said were launched just before 2:00 a.m. (Saturday 1700 GMT) and traveled 350 kilometers at a maximum altitude of 100 kilometers, were loud Kyodo were fired from submarines news agency.

The missiles, which were fired at the East Sea, also known as the Sea of ??Japan, appear to have fallen outside of Japan’s Exclusive Economic Zone, the Japanese government said, according to Kyodo. The Coast Guard said it had not received any reports of damage to Japanese ships so far, national broadcaster NHK reported.

The US military’s Indo-Pacific Command, meanwhile, said in a statement that it was “aware of the two ballistic missile launches and is consulting closely with our allies and partners,” and said the launch demonstrated the “destabilizing” nature of the North Korean missile program.

“US commitments to the defense of the Republic of Korea and Japan remain adamant,” the statement said.

Sunday’s launches were the latest in a spate that included a medium-range ballistic missile fired over Japan on Tuesday, alerting people in affected areas below to take cover.

And on Thursday, North Korea launched two ballistic missiles, on the same day Seoul, Tokyo and Washington conducted new exercises involving a US Navy destroyer from the combat group of the aircraft carrier USS Ronald Reagan.

The United States moved the nuclear-powered aircraft carrier to waters east of South Korea as part of a broad military response to Tuesday’s Pyongyang test, which also included joint bombing and missile exercises.

Yonhap said exercises between South Korea and the United States ended on Saturday.

In addition, Seoul’s military said it grounded 30 warplanes on Thursday after 12 North Korean warplanes conducted a rare “formation flight north of the inter-Korean air border.” [and] conducted air-to-ground firing drills.”

Pyongyang’s foreign ministry earlier this week called the recent launches “the just countermeasures by the Korean People’s Army.”

And on Thursday, the United Nations Security Council held an emergency meeting to discuss the Pyongyang launch over Japan.

The United States called the meeting after officials and analysts said a Hwasong-12 had been fired, probably covering the longest horizontal distance of any North Korean test.

At the meeting, North Korea’s longtime ally and economic benefactor China accused Washington of provoking the spate of launches by Kim Jong Un’s regime, and Chinese Deputy Ambassador to the United Nations Geng Shuang accused the United States of “pousing the regional security environment to poison”.

US Ambassador to the United Nations Linda Thomas-Greenfield has called for existing sanctions on North Korea to be “boosted,” while China and Russia vetoed them in May.

The council was divided for months responding to Pyongyang’s nuclear ambitions, with Russia and China on the sympathetic side and the rest of the council pushing for punishment.

Analysts say Pyongyang has used the opportunity of the UN standoff to conduct increasingly provocative weapons tests.

Kim has declared isolated North Korea an “irreversible” nuclear power, effectively ending the possibility of denuclearization talks.