North Korea is "highly likely" to fire short-range missiles off its east coast after issuing a fresh warning to shipping to stay clear of some areas, a South Korean newspaper said on Thursday.
"It is highly likely that the North will launch missiles" from bases in the eastern provinces of Kangwon and South Hamkyong, the JoongAng Ilbo quoted an intelligence source as saying.
The communist state has responded defiantly to UN condemnation of its long-range rocket launch in April and of its May nuclear test, vowing to bolster its defences.
The source said the North is likely to fire Scud-B missiles with a range of 340 kilometres (212 miles), or Rodongs whose 1,300-km range would likely be shortened to some 400 km for this round of testing.
Ground-to-ship missiles with a range of 140 km may also be fired, the source said. Defence Ministry officials declined to comment.
A military official quoted by Yonhap news agency said there are no signs of preparations to fire mid-range missiles in the near future.
Vehicles with movable launchers have not been seen at a missile base in Anbyon county, the unidentified military official was quoted as saying.
"They are carrying out the usual command post exercises at missile bases but we're watching closely as they can fire short-range missiles at any moment," the official said.
The North issued a fresh warning to Japan on Wednesday to stay clear of some coastal areas during military exercises until July 11, the Japan Coast Guard said.
It issued navigation bans for 10 areas in the Sea of Japan (East Sea) and the Yellow Sea, citing "military gunfire and bombardment training".
US defence officials also said in early June that the North appears to have transported a long-range missile to a new base in the west of the country in preparation for a possible launch.
But there have been no recent reports of preparations for a launch there.
Pyongyang tested long-range missiles in 1998, in 2006 and on April 5 this year when it fired a Taepodong-2 to put a satellite into orbit.
The US and its allies said the real purpose of the launch was to test a ballistic missile theoretically capable of reaching Alaska or Hawaii.
US Defense Secretary Robert Gates said last month the military has beefed up its defenses in Hawaii as a precaution.