THE North Korean army was "deeply split" over whether to support Kim Jong-un as leader, a situation likely to have encouraged his warlike rhetoric in recent weeks, the Daily Telegraph reports.

The news came as a US official told CNN that Pyongyang may test fire its mobile ballistic missiles "at any time". The unnamed official said the test could happen without North Korea issuing a "standard notice to commercial aviation and maritime shipping warning them to stay away from the missile's path".

Word of the factional disputes within the Korean People's Army comes from a defector from the North identified only as 42-year-old First Lieutenant Kim. He told the Telegraph the factions began to turn on each other as soon as it became clear Jong-un was heir apparent in late 2010. Kim, who supported Kim Yong-nam, North Korea's 85-year-old president, says he fled North Korea after he murdered a company commander who was leading a faction loyal to Kim Jong-un.

"There were two fights. In the first fight, they surrounded us and arrested a lot of people," Lt Kim said. "But I got away and gathered others from the barracks. We found them and I shot the commander. After that, I escaped."

Lt Kim said "a lot of people" in the People's Army were opposed to Kim Jong-un, but many of them were arrested after he came to power. Divisions within the military, and the desire of a young leader to consolidate his position, could be one factor behind the current spate of aggression, suggests the Telegraph.

The existence of factions within the North Korean military was confirmed by an analyst who said "rumours of dissension and divisions over who is or who would have been a better leader" were particularly prevalent in the north of the country.

Joseph Bermudez, an expert on the North Korean military and an analyst at DigitalGlobe, added that Jong-un had been alarmed in recent months by a "possibly violent falling-out" between two factions over the control of army reconnaissance. The incident prompted the young leader to reshuffle "a host" of senior army commanders.

Meanwhile, Chinese authorities have told travel agencies to call off some visits to North Korea as tensions on the peninsula continue to escalate, The Guardian reports.