The North Korean Army has test-fired five short-range missiles off its east coast and prohibited ships from entering the area from 10-20 October, according to South Korean military officials.
The official was quoted as saying the launches appear to be part of regular military exercises but did not exclude the possibility that Pyongyang is demonstrating its firepower for political purposes.
The missiles test-fired were the KN-02 missiles with a range of 120km.
The solid-fuel mobile ballistic missile is an improved variant of the Russian SS-21 Scarab missile.
In July 2009 North Korean ground forces test-fired four short-range missiles which were believed to be of the surface-to-ship type.