North Korea has placed two of its intermediate range missiles on mobile launchers and hidden them on the east coast of the country, South Korea's Yonhap news agency reported on Friday, citing intelligence sources in South Korea.
The report could not be confirmed, but may be intended to demonstrate a threat by the North to either Japan or to U.S. bases on Guam. The North has threatened to attack bases on Guam if the United States launches a strike on it.
"Early this week, the North has moved two Musudan missiles on the train and placed them on mobile launchers," Yonhap cited a senior military official familiar with the matter as saying.
South Korea's Defence Ministry declined to comment on the report.
There were unconfirmed media reports that the North had moved missiles to the east coast on Thursday, although it was not clear what kind of missiles had been deployed.
Speculation has centered on two kinds of missiles neither of which is known to have been tested.
One was the so-called Musudan missile which South Korea's Defence Ministry estimates has a range of up to 3,000 km (1,865 miles), the other is called the KN-08, which is believed to be an inter-continental ballistic missile, which is again untested.
South Korea's defence minister has said he does not believe the missile that was moved was the KN-08.
North Korea has slowly and steadily improved its missile capabilities in recent years and U.S. officials say its missiles may be capable of hitting outlying U.S. territories and states, including Guam, Alaska and Hawaii.
Some private experts say even this view is alarmist.
There is no evidence, the officials say, that North Korea has tested the complex art of miniaturizing a nuclear weapon to be placed on a long-range missile, a capability the United States, Russia, China and others achieved decades ago.
North Korea has been engaged in month-long war of words with the United States and South Korea in the wake of Washington-led sanctions imposed for its February nuclear test.
It has threatened to stage a nuclear strike on the United States, to attack bases on Guam and said a state of war exists on the Korean peninsula.