While the rest of the world watched anxiously for any sign of unrest, North Koreans began a period of intense public mourning Tuesday as Kim Jong Il's body was laid out in a memorial palace in a glass case.

Weeping mourners filled public squares and plazas, their sorrow broadcast by official state media and picked up by news organizations around the world.

Footage emerged Tuesday of Kim Jong Un, successor to Kim Jong Il, publicly paying his respects to his father. Little is known about Kim's youngest son, but his appearance Tuesday with top military and Workers' Party officials was a strong indication that the transition is underway.

Kim Jong Un, clad in a black Mao-style suit with his hair cropped short at the sides, bowed solemnly toward his father's coffin. After he had paid his respects, North Korean dignitaries were allowed to file past, weeping as they paid their respects.

CTV's Janis Mackey Frayer, reporting from Seoul, South Korea, said the grief was palpable.

"People are wailing, they're convulsing, they're overcome with sadness, they're talking about missing this great man who did so much for their country," Mackey Frayer told Â鶹´«Ã½ Channel.

"And there's the expectation that people are doing this out of some sense of duty or loyalty because they were raised to -- but they are being genuine in their grief as well."

She said the North Koreans appear to have an emotional attachment to the man known as the "Dear Leader," and are pledging to offer the same kind of commitment and loyalty to his son.

Flags flew at half-staff at government buildings, businesses, military bases and on homes and farms. Groups of mourners gathered at landmarks across the capital to lay bouquets and wreaths.

"We will change today's sorrow into strength and courage and work harder for a powerful and prosperous nation, as our general wanted, under the leadership of the new general, Kim Jong Un," Pyongyang resident U Son Hui told The Associated Press.

Meanwhile the world's super powers and South Korea's neighbours watched anxiously for signs of tension or unrest in the communist country with nuclear capabilities.

Mackey Frayer said there are many question marks surrounding Kim Jong Il, his son and successor Kim Jong Un, and the future of the country.

"It's that great unknowable that's stirring a lot of the unease," she said.

Mackey Frayer said South Korea was in a state of alert Tuesday but was not at the highest possible level, known as "combat ready."

South Korea, which is technically still in a state of war with North Korea, made a significant gesture of goodwill towards Pyongyang on Tuesday by offering public condolences to the people of North Korea.

Seoul also took the exceptional measure of saying some North Koreans living in South Korea would be allowed to travel to their homeland to attend the memorials for Kim.

However, South Korea made it clear no official delegation would be travelling to Pyongyang. In fact, North Korea said only its close ally China would be allowed to send a delegate to the ceremonies.

Ri Ho Il, a lecturer at the Korean Revolutionary History Museum, told The Associated Press in Pyongyang the Korean people were in "deep sorrow at the loss of the benevolent father of our nation."

"He defended our people's happiness, carrying on his forced march both night and day," Ri said.

Images and video that aired on official state TV showed the glass coffin holding Kim's body was surrounded by red "kimjongilia" blossoms -- the flower that bears his name. He was covered with a red blanket.

The coffin was on display in the Kumsusan Memorial Palace, the same location where the body of Kim's father Kim Il Sung has been on display since his death in 1994.

The country will observe an 11-day period of official mourning -- during which all forms of entertainment will be banned -- and a state funeral will be held on Dec. 28.

For the first time, the Korean Central News Agency on Tuesday described Kim Jong Un as "a great person born of heaven," a propaganda term previously used only for his father and grandfather.

Mackey Frayer said it isn't clear how much power Kim Jong Un will immediately possess or how great his responsibilities will be. His sister and brother-in-law, who have been largely responsible for running the country since his father fell ill several months ago, will likely play a key role, she said.

"He's not going to be running this alone. There is a very tight inner political circle."

The Rodong Sinmun, the newspaper of the ruling Workers' Party, added in an editorial that Kim Jong Un is "the spiritual pillar and the lighthouse of hope" for the military and the people.

Kim Jong Il, once described by former U.S. president George W. Bush as a "tyrant," had been groomed for 20 years to lead the communist nation founded by his guerrilla fighter-turned-politician father.

There are few details known about the country and Kim Jong Il," and there are also conflicting reports as to when the leader was born.

Although legend has it Kim was born on Mount Paekdu in 1942, Soviet records claim he was born in Siberia in 1941 while his parents were in exile.

Kim Jong Il, who graduated from Pyongyang's Kim Il Sung University, was 33 when his father tapped him as his successor.

Even before he took over as leader, there were signs the younger Kim would maintain -- and perhaps exceed -- his father's hard-line stance. During his years in power he carried out his father's "military first" policy by devoting much of the country's resources to troops. He built the world's fifth largest military even while the country suffered through a prolonged famine.

Kim also strived to build up the country's nuclear arms arsenal, culminating in North Korea's first nuclear test explosion, in October 2006. Another test followed in 2009.