Millions of North Koreans wailed in grief for their former leader Kim Jong Il during an elaborate state funeral that cemented his youngest son as his successor.

Kim Jong Un was head mourner in the funeral, walking with one hand on the black hearse that carried his father's coffin on its roof, his other hand in a salute.

Ceremonial head of state Kim Yong Nam told a sea of people in Pyongyang's main plaza that Kim Jong Un inherits his father's "ideology, character and revolutionary" cause.

Speaking to Â鶹´«Ã½ Channel from London, CTV's Ben O'Hara-Byrne said the formation of the funeral procession revealed clear signals that the power brokers in the country have rallied behind Kim Jong Il's son.

"You saw Kim Jong Un, the great successor, walking right up front alongside his father's hearse," he said. "Behind him, his uncle, just a few steps behind, his powerful uncle, married to Kim Jong Il's sister. On the other side of the hearse: the top military officials."

O'Hara-Byrne pointed out that the son needs their support because he was not groomed for the position, which he now holds.

"He is a man of mystery," he said. "We do know he is in charge of one of the largest armies in the world. But he won't be leading alone."

On a bitterly cold, snowy day in the capital of Pyongyang, the 28-year-old new leader walked at the front of a 2 ½-hour procession

Goose-stepping soldiers marched by while thousands in the crowd wailed and stamped their feet in grief, although some have questioned the authenticity of the tears.

Mourners in parkas lined the streets, waving, stamping and crying as the convoy passed. Some struggled to get past security personnel.

North Korea's state media claimed that millions of people lined the sides of the funeral route.

The New York Times reported on Wednesday night that the photo of the funeral procession released by North Korea's state news agency and transmitted by the European Pressphoto Agency appears to have been altered.

In the photo, a group of men standing near a camera behind the assembled crowd were removed. A second photo taken by a Japanese agency Kyodo News reveals the changes, the Times reports.

Foreign diplomats were invited to attend the procession, though few other outsiders appeared to be allowed into the country for the funeral.

One foreign diplomat in Pyongyang said that funeral music played as the convoy left Kumsusan Memorial Palace, where Kim's body had lain in state.

The diplomat also said that people put scarves and even jackets on the roads to try to stop the snow from causing problems on the route.

"There is some advanced theatre of grief on display in Pyongyang," said O'Hara-Byrne, who was on assignment in North Korea several years ago. "When the cameras are on, you better cry in a one-party police state."

During an appearance on CTV's Canada AM, Carleton University political science professor Jeremy Paltiel described the wailing as "a performance of loyalty."

"This is a family-centred regime," he said. "Everyone depends on loyalty to the leader for whatever privileges they have."

Paltiel also noted that the new leader has not had the advantage of being groomed by his father for 15 years before taking power.

"He is also much younger than his father was in 1994 (when the father took over)," he said.

Analysts have also raised questions about the son's inexperience and how that might hinder him in facing the challenges of feeding a country where some are starving, yet maintaining a nuclear weapons program that has the world on edge.

"It's a very complex state to operate," York University Asian studies professor Donald Rickerd told Canada AM. "He's a 28-year-old with a very shaky record. He's very untested."

During the funeral, even the soldiers got emotional as they watched the hearse containing the body of Kim Jong Il, who died of a heart attack Dec. 17 at age 69.

"How can the sky not cry?" a weeping soldier told state TV. "The people ... are all crying tears of blood."

Now the country will prepare for Thursday's memorial ceremony when tributes to Kim Jong Il will be read to the crowd.

"The message will be clear: Kim Jong Un now lead the country and there is no alternative," said Kim Yeon-su, a North Korea expert at the state-run Korea National Defence University in South Korea.

North Korea says that Thursday's memorial service will start at noon.

But for those outside the country, the crowd around Kim Jong Un on the dias should reveal his inner circle. Key among them will be his uncle Jang Song Thaek, Kim Jong Il's brother-in-law and a vice chairman of the powerful National Defence Commission.

With files from The Associated Press