German police have arrested 21 West Ham and Newcastle United football fans after they were involved in violent clashes while in the country for a pre-season tournament, it has been reported.

Fighting broke out after around 300 fans were drinking in bars in Dusseldorf city centre last night, according to police.

Fans of the two teams made the trip to Germany to follow the Schalke Cup, in which they are due to take on Malaga and Schalke as they prepare for the start of the new Premier League season.

A spokesman for Dusseldorf Police said: "There were 300 English fans in the city centre. The fans from both clubs met and first of all they had some beers on their own, and when they met the other club there has been some verbal arguments. After that they had a physical fight.

“We put 100 policemen in the city centre so that things would calm down and it calmed down very fast but we made 21 short term arrests.”

It is not known how many fans from each team were involved.

Newcastle and West Ham fans clashing in Germany today. pic.twitter.com/Gz4vAkJKgw — The Away Fans (@theawayfans) August 1, 2014

Sam Rees, who runs a Newcastle United fan site, was sent images of the clashes but said it was unclear whether the violence was sparked by supporters or a football hooligan gang.

She told the Newcastle Chronicle: “I just thought we were having such a good time at the moment in the press and then we have this sheer stupidity from some people and it just makes us ashamed.”

Both teams were due to be in action this afternoon.