SEOUL –- North Korea test-launched two medium-range ballistic missiles early Wednesday in violation of U.N. Security Council resolutions, officials said.
The South Korean military said the missiles were launched just after 2:30 a.m. and flew for a little more than 400 miles.
The U.S. State Department said the two missiles flew "over North Korea's land mass and impacted in the Sea of Japan." It appeared that North Korea did not issue maritime warnings about the launches, the department said. No one was reported killed or injured.
"We are closely monitoring the situation on the Korean peninsula," said Marie Harf, a State Department spokeswoman. "We urge North Korea to exercise restraint and refrain from further threatening actions."
Kim Min-seok, a spokesman for South Korea's Ministry of National Defense, also called for North Korea to cease "provocative behavior."
"Our government is intensifying monitoring of North Korea's military and preparing for all possible outcomes," Kim said, according to the Dong-A Ilbo newspaper.
In recent weeks, North Korea has intermittently fired short-range artillery missiles, including a volley of 30 on Monday. Those missiles weren't deemed to be much of a threat by South Korea or the United States. because of their limited range.
The U.S. said United Nations Security Council resolutions require North Korea to suspend its ballistic-missile program and reestablish a moratorium on missile launches.
The launches Wednesday came as annual military exercises between U.S. and South Korean forces were underway in South Korea. The exercises were scaled down this year, with the apparent intention of being less provocative to North Korea.
This year's drills, which are scheduled to end April 18, do not include an aircraft carrier or B-52 bombers. A previous exercise consisted almost entirely of computer simulations. Though the exercises are defensive in nature, the North Korean government in Pyongyang objects to them, describing them as rehearsals for an invasion. Approximately 28,500 U.S. troops are stationed in South Korea.
The missile launches also came on the fourth anniversary of the sinking of the South Korean warship Cheonan, in which 46 sailors died. Seoul attributes the sinking to a North Korean torpedo attack; North Korea has denied any involvement.
Signs of a possible detente had been evident in recent months after years of unfriendly relations on the Korean peninsula. For the first time since 2010, the two sides in February allowed reunions of family members divided by the Korean War. However, after the reunions, Pyongyang rejected the South's offer to hold talks on holding the family meetings on a regular basis.