North Korea's propaganda campaign has surged into the 21st century with a new Twitter account, hot on the heals of its foray into video with clips posted on YouTube.

The secretive regime has begun micro-blogging under the name @uriminzok, with a number of posts pointing its few dozen followers to anti-Seoul and anti-US statements on the country's official website (http://www.uriminzokkiri.com).

South Korea blocks the site and few in North Korea have access even to a computer.

One tweet dismissed accusations that a North Korean torpedo sank a South Korean warship in March. Another critisiced US-led sanctions on North Korea and Iran.

Most followers posted derisive comments in Korean.

Tensions on the peninsula have risen sharply since late May when South Korea and the United States, citing a multinational investigation, accused the North of attacking a South Korean warship, the Cheonan, near the contested border.

The North vehemently denies involvement in the incident.

Last month it opened an account with YouTube, a popular global video-sharing site, uploading video clips which praised leader Kim Jong-Il and denying its role in the sinking.

North Korea operates an army of elite hackers. South Korea's spy agency has said that the North was behind cyber attacks that briefly paralysed the web sites of South Korean and US government agencies and commercial organisations last year.