North Korea's new leader Kim Jong-Un issued his first military order just before his father's death was announced, suggesting the son already controls the armed forces, a report said Wednesday.

Jong-Un ordered all units to halt field exercises and training and return to their bases, Yonhap news agency quoted a senior Seoul government source as saying.

"This is clear-cut evidence that Kim Jong-Un has secured a firm grip on the military," the official was quoted as saying.

Pyongyang announced at noon Monday (0300 GMT) that leader Kim Jong-Il had died of a heart attack two days earlier. State media has proclaimed his son as the isolated communist nation's new leader.

Comments by the head of the South's National Intelligence Service appeared to back up the Yonhap source.

Won Sei-Hoon told parliament Tuesday that a North Korean unit test-fired two short-range missiles off its east coast before noon Monday.

But they cancelled their plan to launch more missiles in the afternoon and returned to base, Won said.

Jong-Un was made vice chairman of the ruling party's Central Military Commission and a four-star general in September last year as his father groomed him for the succession.

The country's regular armed forces total 1.19 million and the regime has a Songun (military-first) policy prioritising its needs over those of civilians.

Other officials quoted by Yonhap said there was no unusual activity in border areas of the North, but more troops had been posted in the Joint Security Area around the border village of Panmunjom.

An intelligence official said the North may be trying to prevent defection attempts during the leadership transition.

Hundreds mourn Kim in China border city
Dandong, China (AFP) Dec 21, 2011 - Hundreds of people, many in tears, flocked to the North Korean consulate in the Chinese border city of Dandong on Wednesday to pay their respects to the isolated country's late leader.

Mourners placed wreaths and bouquets of white and yellow flowers below a large portrait of Kim Jong-Il, who died of a heart attack in Pyongyang on Saturday at 69, triggering mass mourning in North Korea.

Many appeared to be from North Korea, and were wearing enamelled lapel pins bearing the likeness of Kim or his father, Kim Il-Sung, on their winter coats and dark suit jackets.

Dandong, a city of 2.5 million people in northeast China, is the main portal for trade with impoverished North Korea, which depends heavily on its wealthier neighbour for oil and food.

On Wednesday an AFP correspondent saw at least 10 fully loaded cargo trucks crossing into North Korea on a bridge linking the two countries.

On the North Korean side of the border, across the Yalu river, flags could be seen flying at half-mast, while in Dandong itself, North Korean restaurants and export businesses were closed.

An AFP reporter in Dandong said there appeared to be fewer North Koreans in the town than usual, and hotel staff reported that many North Korean guests had checked out after Kim's death was announced.

A consular official told AFP visas for Chinese individuals would not be granted until after the mourning period ends on December 29.

Visitors to the consulate paid their respects in silence before being moved on by guards. They declined to speak to AFP about Kim's death, many shying away from having their photographs taken.

Guards allowed them to linger long enough to leave flowers, bow deeply from the waist to Kim's portrait and pause at a television playing a documentary about the former dictator.

Local vendors outside set up temporary flower stalls on street corners, selling chrysanthemum blooms that China's official Xinhua news agency said were brought in from neighbouring areas to meet strong demand.

Nearby peddlers sold souvenir 5,000 North Korean won notes for 20 yuan ($3.15), framed in plastic sheets protecting the pictured faces of Kim and his late father, North Korea's founding president Kim Il-Sung.

China has sought to boost trade so as to encourage its isolated and hardline neighbour to embark on market-oriented economic reforms. Trade surged an annual 87 percent in the first seven months of this year to $3.1 billion.

The two nations share a 1,415-kilometre (880-mile) border and a significant portion of all trade between North Korea and the outside world comes by road and rail through Dandong.

Beijing has for years propped up the regime in Pyongyang, fearful that a collapse would lead to a wave of refugees flooding into China.

Already, an estimated 22,000 North Koreans have fled their hunger-stricken homeland since the 1950-1953 war, the vast majority in recent years. Most escape via China and seek eventual resettlement in South Korea.

A Chinese taxi driver in Dandong who gave only his surname, Wang, told AFP that since he was a child, more and more North Koreans had come to live in his home town.

"I don't have much to do with them. They keep to themselves, take their own transport," Wang said.