North Korea has launched another ballistic missile early Tuesday that flew over Hokkaido island before crashing into the sea. The Japanese prime minister denounced the launch as an “unprecedented and grave threat” to the country’s security. Tokyo warned citizens in the north of the country to take shelter.

The missile, thought to be a new intermediate-range Hwasong-12, flew over Hokkaido and landed in the Pacific, South Korean and Japanese officials said. Seoul’s joint chiefs of staff (JCS) said the missile travelled about 2 thousand 700 km and reached a maximum altitude of 550 km.