The North fired two missiles Saturday morning and another in the afternoon, South Korean Defense Ministry spokesman Kim Min-seok said by phone. He said the North's intent was unclear. His ministry said it is watching North Korea carefully in case it conducts a provocation against South Korea.
In March, North Korea launched what appeared to be two KN-02 missiles off its east coast. Experts believe the country is trying to improve the range and accuracy of its arsenal.
North Korea recently withdrew two mid-range "Musudan" missiles believed to be capable of reaching Guam after moving them to its east coast earlier this year, U.S. officials said. The North is banned from testing ballistic missiles under U.N. Security Council resolutions.