North Korea fired off a volley of three ballistic missiles from its west coast Monday that fell within Japan’s exclusive economic zone, a move that Tokyo called a grave threat to national security amid Pyongyang’s growing ability to strike the Japanese archipelago.

The North launched the missiles from near Hwangju, North Hwanghae province, at around 12:13 p.m., according to the Defense Ministry. The three missiles flew about 1,000 km and fell about 200 km to 250 km west of Okushiri Island off the western coast of Hokkaido. The ministry said that the missiles were likely to have been short-range Scud missiles or Nodong medium-range ballistic missiles, which have a striking range that includes Japan, the ministry said.

Chief Cabinet Secretary Yoshihide Suga said that Tokyo had lodged a protest — using "the strongest terms" — with the North through its embassy in Beijing.