North Korean leader Kim Jong Un visited his grandfather Kim Il Sung's mausoleum to commemorate the 25th anniversary of the founder of the reclusive communist country's death.

The Kumsusan Palace of the Sun, where the embalmed bodies of Kim Il Sung and late leader Kim Jong Il lie, and bowed in front of the statues.

North Koreans observed a three-minute silence at midday local time (0300 GMT) on Monday.

Pyongyang residents were also seen bowing their heads on streets, boats and public squares, as sirens went off for to signal a minute of silence.

Paying respects in this way is required on all main anniversaries and holidays, and not just at the giant statues in downtown Pyongyang, but at images of the past leaders all over the country.

Kim Il Sung led his country from its founding in 1948, through the 1950-53 Korean War, and until he died in 1994. He was succeeded by his son, Kim Jong Il, who died in December 2011.

Kim Jong Un took over then, and North Korean authorities have continued to increase the requirements on citizens to demonstrate loyalty to this leadership system.

Therefore, North Koreans are extremely careful when talking in public about their leaders, especially in front of foreign media.