It comes amid a wave of anti-US sentiment which flared up last year following the deaths of two Korean schoolgirls, run over by a US military vehicle.

The protesters insisted most South Koreans were in favour of the continued presence of US troops.

The rally was led by South Korean war veterans who waved pro-US placards outside Osan military base.

US troops are in South Korea as a deterrent against an attack from North Korea.

There are 37,000 US troops in the country, under a mutual defence pact.

Recent protests have called for the pact to be changed.

Anti-American protests have subsided, as the spotlight turns to North Korea's nuclear programme.