The Red Devils started well in Lille and took an early lead through a blistering Radja Nainggolan strike.

But Wales hit back to equalise through an Ashley Williams goal before man of the match Hal Robson-Kanu and substitute Sam Vokes both netted in the second half to send Belgium home.

"I think our strategy was good because for 25 minutes we played excellently, getting forward, dominating, and then suddenly we started to drop back," Wilmots said.

"I didn't stop shouting at them to push out but it's difficult when they are out on the pitch. I was making big gestures as well.

"Maybe they were afraid of leaving space in behind. Maybe there were problems with communication as well but I am not a magician." Belgium's defence was hit by the absences of centre-back Thomas Vermaelen due to suspension and left-back Jan Vertonghen, who tore ankle ligaments in training on the eve of the game.

With Vincent Kompany having been ruled out before the tournament began, youngsters Jason Denayer and Jordan Lukaku came into the line-up and endured a torrid evening against the Welsh attack.

"We had a defence with an average age of 23. I am responsible. A team needs to be developed and well-oiled. In the previous three matches we hadn't conceded a goal and then here we had to change half our back line," Wilmots said.

"We lost one player who injured himself at the last minute in training. I think that was a bit too much.

"The first goal we lost was from a set-piece, something that hadn't happened to us in 30 games. We made errors that we couldn't afford to make.

"I don't know if you can put it down to youth but in any case I am responsible."

Goalkeeper Thibaut Courtois felt that Belgium had been punished for making the same mistakes as in their opening game, a 2-0 defeat to an Italian side who played in the same 3-5-2 system as Wales.

"Against a 3-5-2 we played with the same tactics and had the same problems. I need to measure my words because I don't want to destroy everything," said the Chelsea player.

"I said what I had to say after the match in the dressing room. I pointed my finger where it had to be pointed.

"It is the biggest disappointment of my career."

- Penalty shout -

Wilmots, who felt that Belgium should have had a penalty for what he saw as a foul on Nainggolan in the area when Wales were leading 2-1, believes his young side can learn from their defeat.

"I am sure they have definitely learnt things tonight because you always learn in tough times, so it's not all lost," he said of a side that had already lost in the quarter-finals of the World Cup two years ago.

"When you are talked about among one of the teams who can win a tournament, and you lose in the quarter-finals twice in two years, of course it leaves a bad taste in your mouth.

"But we made too many mistakes to win this match against a very good Wales side, who know how to play football." However, Wilmots -- who has been heavily criticised by sections of the Belgian press -- refused to take an immediate decision on whether he will continue as coach.

"I have said that I would make a decision after the Euros but I won't make one straight after the game. I'm going to take my time and think about it."