North Korea will likely fire short- or mid-range missiles in waters off its east coast from which it has banned shipping, a senior South Korean government official said Wednesday.
The North has warned foreign ships to stay clear of an extensive area for 16 days starting Thursday because of unspecified military exercises.
"I think so," the official told foreign correspondents when asked if the North was preparing to fire short-range or mid-range missiles.
Yonhap news agency, quoting a government source, said the communist state would probably fire Scuds with a range of up to 500 kilometres (312 miles) or ground-to-ship missiles with a 160-km range into the Sea of Japan (East Sea).
Washington has said it is prepared for the possibility that the North could also fire a long-range missile towards Hawaii, perhaps on the July 4 US Independence Day.
The official, speaking on condition of anonymity, said preparations were under way to fire a long-range missile "but I'm not sure they can immediately launch."
Pyongyang's last long-range rocket launch on April 5 triggered the latest period of regional tension.
Angry at UN condemnation of the firing, the North quit international nuclear disarmament talks and staged its second nuclear test on May 25.
In the days after the test the North also fired six short-range missiles off its east coast and renounced the truce in force on the Korean peninsula, prompting South Korea to reinforce its military on the tense border.
The UN Security Council on June 12 slapped new sanctions on the North tightening a ban on arms shipments among other measures. A US destroyer is now shadowing a suspicious North Korean cargo ship apparently heading for Myanmar.
The Seoul official said the North's recent aggressive activities appear linked to the issue of who will succeed leader Kim Jong-Il.
South Korean intelligence officials have been quoted as saying the 67-year-old ailing leader has chosen his youngest son Jong-Un. The official agreed it was fairly likely Jong-Un had been selected.
"The regime's top priority will be to consolidate its power base," the official said.
Unlike Kim himself when he took over, the official said none of his sons had close relations with high-ranking officials in the ruling elite.
When the succession takes place there is the possibility of a power struggle, the official added. "This is why we are watching and are concerned about it."