SEOUL, March 17 (UPI) -- North Korea fired at least one ballistic missile into waters off the eastern coast of the peninsula Friday.
The launch was not made public on Pyongyang's media networks, but South Korea's Joint Chiefs of Staff said the missile, fired around 5:55 a.m., fell into the East Sea, also known as the Sea of Japan.
The missile flew about 500 miles before it fell into the water, Yonhap reported.
The object is most likely a mid-range Rodong missile, similar to the weapon fired in March 2014, and could have been followed by the launch of a second weapon.
The second missile disappeared from the radar at an altitude of 11 miles, and could have detonated mid-air before reaching its target, Seoul's Joint Chiefs said.
The Rodong has a maximum range of 800 miles and could easily hit all parts of South Korea, and part of Japan.
On March 10, North Korea said it launched two short-range ballistic missiles into the East Sea and claimed the tests were "carried out by detonating the nuclear warhead at a designated altitude in the target area," according to Daily NK.
But the explosion was not detected, partly due to the location of the test in North, but also because of the low magnitude of the alleged explosion.
The tests are coming at a time of tensions between the North and the United States -- and the arrest of a 21-year-old U.S. student in Pyongyang in January has only added more pressures.
The case of Otto Warmbier has led to denunciations from Washington, and on Thursday, Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford said at a Senate Armed Forces Committee hearing that the detention was a "reflection of the absolutely irresponsible leadership" of Kim Jong Un.
Dunford also said in statement that although the United States keeps a military advantage against the relatively less-advanced North Korean army, an armed conflict could still lead to numerous deaths, Yonhap reported.