Japanese intelligence services indicate North Korea (search) may be preparing to test launch a short-range missile, a Japanese newspaper reported Thursday.

Information from spy satellites and radio waves has shown North Korea beefing up troops and equipment around missile launch bases, the daily Yomiuri Shimbun (search) reported, citing unidentified government sources.

The secretive communist nation has test-fired short-range missiles into the ocean on several occasions last year.

In Seoul (search), Rhee Bong-jo, the deputy unification minister, said South Korea recently detected activity "connected to North Korean missiles."

South Korea believes "there is a high possibility that these were part of the annual, routine activities of North Korean missile units," Rhee said Thursday. "But since we cannot rule out a possibility of a missile launch, we are continuously monitoring and trying to confirm the situation."

A Japanese foreign ministry official, speaking on condition of anonymity, refused to confirm the Yomiuri report. But he told The Associated Press that Japan is constantly monitoring the possibility of a North Korean missile launch.

Nodong missiles have a range of about 810 miles and would be capable of striking parts of Japan's main islands, the Yomiuri said. Officials estimate that it could be about two weeks before a possible launch.

Japan dispatched an Aegis-equipped destroyer and other surveillance equipment to the Sea of Japan on Tuesday evening following the discovery, the Yomiuri said.

A Maritime Self-Defense Forces official, speaking on condition of anonymity, told the AP that the Aegis destroyer Myoko had left port for training. The official spoke from Maizuru, the home port of the vessel identified in the Yomiuri report.

Officials are also preparing for the possibility of a longer-range launch of a Taepodong ballistic missile, the Yomiuri said.

North Korea launched a Taepodong missile over Japan's main island and into the Pacific Ocean in 1998, demonstrating that virtually any target in Japan was within its range.

The Defense Agency said it had no comment and a spokesman for the prime minister said he had no information when contacted by the AP.