SEOUL, March 22, /ITAR-TASS/. North Korea test-fired 30 short-range rockets into the Sea of Japan, a spokesman for South Korea’s Joint Chiefs of Staff reported Saturday.

The rockets were launched starting at 4 a.m. local time (19:00 GMT) and are estimated to have flown 60 kilometers (37 miles), South Korea’s Yonhap news agency quoted the country’s military as saying.

North Korea fired dozens of rockets in March in what Seoul believes was a protest against ongoing joint military exercises of South Korea and the United States, entitled Foal Eagle, that Pyongyang traditionally calls a preparation for invasion of the North by the allies.