PYONGYANG • Tens of thousands of North Koreans turned out to pay tribute to their leaders yesterday, the most important day of the isolated, nuclear-armed country's ritual calendar.

In North Korea, April 15 is known as the Day of the Sun, the anniversary of the 1912 birth of the country's founder Kim Il Sung, whose son Kim Jong Il succeeded him. His grandson Kim Jong Un, the current leader, inherited power in turn.

North Koreans are taught from birth to revere the Kim family, and the ceremonies surrounding such occasions are one of the ways in which the authorities reinforce loyalty.

From early morning, a steady stream of citizens arrived at Mansu hill in Pyongyang, where giant bronze statues of the two elder Kims look out over the capital. Platoons of soldiers, staff of work units, families, newlyweds and tourists all lined up before the images, advancing to place flowers at their base.

"Let us pay tribute to the great president Kim Il Sung and the great leader Kim Jong Il," intoned an announcer half-hidden by floral baskets, and all bowed in unison, the troops saluting.

Retired colonel Ra Man Ok, 84, wiped tears from her eyes as she stood before the statues, took a few paces backwards still facing the images, and bowed an extra, second time.

"I want to pay tribute with my spirit to the great leaders because I am too old to repay their benevolence with my labour," she told Agence France-Presse, wearing the uniform in which she had marched in a military parade decades ago.

"My motto is that everybody can realise their hopes only by following the leadership of our party through all trials and difficulties."

Ordinary North Koreans always express wholehearted support for the authorities when speaking to foreign media.

In pride of place before the statues, cordoned off with a chain, stood a giant floral tribute in the name of Mr Kim Jong Un.

This year's anniversary - which is also marked by other events including mass dances and a flower festival - comes days after Mr Kim reinforced his already unshakeable grip on power with a generational reshuffle in the Supreme People's Assembly, the country's rubber-stamp legislature.

The nonagenarian head of the Parliament, Mr Kim Yong Nam - who also acts as the North's ceremonial head of state, as Mr Kim Il Sung officially remains Eternal President despite dying in 1994 - was replaced by Mr Choe Ryong Hae, considered one of Mr Kim Jong Un's right-hand men. Outgoing premier Pak Pong Ju, who turned 80 last week, made way for Mr Kim Jae Ryong.

At the Kim statues yesterday, engineer Ri Yang Myong, 60, said: "I will fulfil my responsibility to uphold the leadership of the respected Marshal Kim Jong Un and will ensure my sons become loyal men who loyally follow the leadership of the respected marshal."

He had brought his five-year-old granddaughter Ji Ye to the statues for the first time, he said, to teach her that it was a family tradition.

"Visiting this place on the national holidays is the law in my family," he added. "I want to make sure she has a loyal spirit."