Jan 10, 2011 14:08 GMT  ·  By

Hackers have hijacked North Korea's YouTube and Twitter propaganda accounts and used them to mock Kim Jong-un, heir-apparent to the country's leadership, on his birthday.

The accounts were created in August last year under the username uriminzokkiri, which means "our nation" in Korean, and were tied to a Pyongyang-based propaganda agency.

After being hijacked on Saturday, they were used to criticize North Korea's supreme leader Kim Jong-il and his son Kim Jong-un.

Messages posted on Twitter described the two as "our people's sworn enemies" and blasted them for creating nuclear weapons.

Another tweet noted that Kim Jong-il hosts parties at his house while 3 million North Koreans are starving to death.

Meanwhile, the hijacked YouTube account was used to post a two-minute spoof video depicting Kim Jong-un running over women and children in a sports car.

It also showed a train filled with gifts for his birthday which derailed after colliding with children sitting on the tracks.

The identity of the hackers is not known, but according to Reuters, people were seen taking credit for the attacks on a South Korean forum called Dcinside.

Little is known internationally about Kim Jong-un, Kim Jong-il's third and youngest son, who is expected to rule the country after his father.

Even his age is uncertain. He is believed to have been born on January 8, 1983 or 1984, which would make him 27 or 28 years old.

He is a four-star general in the North Korean People's Army and is said to have had computer science training.

Some sources even claim that he leads the army's division of hackers which is regularly blamed by South Korea for attacks against its Internet infrastructure. Internet access in North Korea is strictly controlled, being allowed only for senior officials.