North Korea has named a new army vice marshal, state media said Tuesday, a day after it announced the communist country's army chief had been relieved of all his posts.

"Hyon Yong-Chol was awarded the title of vice marshal of the Korean People's Army," Pyongyang's official Korean Central News Agency (KCNA) said Tuesday.

The decision was taken on Monday by the ruling party's Central Military Commission and the country's National Defence Commission, KCNA said in a brief statement.

Little is known about Hyon, who became a general in September 2010 along with five others including new leader Kim Jong-Un and his aunt Kim Kyong-Hui.

Professor Yang Moo-Jin of the University of North Korean Studies in Seoul said Hyon was an enigmatic person although he is believed to be from a family who fought alongside North Korea's founding father Kim Il-Sung against Japanese colonialists.

Hyon is now one of the four vice marshals in the North.

The other three are Director of the General Political Bureau of the North Korean army, Choe Ryong-Hae, Armed Forces Minister Kim Jong-Gak and Vice Chairman of the decision-making National Defence Commission Kim Yong-Chun.

It was the latest shake-up in the North's powerful military after Vice Marshal Ri Yong-Ho was relieved of all his posts on Sunday.

Ri was a visible figure and key support for North Korea's leader Kim Jong-Un following the death in December of his father Kim Jong-Il, the North's longtime dictator.

Illness was given as the official reason for Ri's departure but analysts expressed scepticism, saying the move showed the young leader tightening his control over the powerful military.

"Hyon is highly likely to succeed Ri Yong-Ho as the chief of the general staff of the army," Yang said.

Hyon is a member of the party's 120-member central committee. But he has not joined the powerful Central Military Commmission of the party, which is chaired by Jong-Un.

Cheong Seong-Chang of Sejong Institute said since his promotion to a general in 2010, Hyon had been drawing attention as one of the key figures expected to help Kim Jong-Un gain control over the military.

"It appears that the North is taking steps to appoint Hyon to replace Ri," Cheong said.

He is likely to take over from Ri as the chief of the general staff of the army, a member of the Presidium of the Politburo of the party Central Committee and a vice chairman of the Central Military Commission, Cheong said.

"Hyon's advance is a surprise," Cheong said, noting that Hyon had not joined the powerful Central Military Commmission of the party and had never accompanied the leader during his public appearances this year.

The North's military has in recent months ratcheted up hostile rhetoric towards South Korea and its President Lee Myung-Bak, partly in a bid to burnish Jong-Un's credentials.

Ri, at a massive anti-Seoul rally in Pyongyang in March, called South Korean leaders "mad dogs" and "psychos" and declared a "sacred war" against Seoul for allegedly insulting the North's leadership.

The impoverished but nuclear-armed North last month also denounced US-South Korean drills near the tense border as a provocation and vowed to bolster its "nuclear deterrent".

It was the latest sign of high tensions after the North's failed rocket launch in April, seen by the United States and its allies as an attempted ballistic missile test.