North Korea fired four ballistic missiles into the waters off Japan on Monday, causing panic in Tokyo and in South Korea. Three of the banned missiles reportedly landed in Japan’s exclusive economic zone, an offshore area where Tokyo has rights to explore resources. The launch is the latest in a series in recent months, as North Korea accuses Washington and Seoul of planning to invade during recent military drills. The launch has prompted South Korean authorities to call for the early deployment of the American missile system Thaad, or Terminal High-Altitude Area Defense, a system that China has cautioned against using. The missiles launched Monday flew about 620 miles, though it wasn’t immediately clear what kind of missiles were used. Japanese Prime Minister Shinzo Abe said the incident shows that North Korea poses “a new kind of threat,” amid widespread fears that the country may soon begin testing intercontinental ballistic missiles capable of reaching U.S. shores. South Korean authorities said they pinpointed the location of the launch as an area in North Pyongan province. The area houses the North’s Seohae Satellite Station, where the country has carried out banned long-range rocket launches recently. South Korean and U.S. troops are conducting military drills on the Korean Peninsula, a move that Pyongyang sees as a hostile threat.