"As England manager I am very concerned at the threat now hanging over us," said Hodgson. "We have worked very hard to get here and desperately want to stay in the competition.
"We appreciate all your support at the matches, of course, but I am appealing to you to stay out of trouble and to try to make certain that these threats being issued are never carried out and we will be able to attempt to do the best we can to stay in this competition by football means."
Rooney added: "Now we have a big game coming up against Wales and I'd like to ask fans without tickets not to travel and those with tickets to be safe, be sensible and continue with your great support for the players.