About 3,000 raucous fans, mostly local children proudly wearing their football kits, cheered the players on during a session at Saint-Pierre on Wednesday.
However, around 200 youngsters were stopped from entering the stadium by security who had planned for a crowd of no more than 3,000.
"The fact 200 fans stayed at the door is unacceptable," Domenech told reporters on Thursday. "They were kids, not hooligans.
"I don't know who took the decision but it's a scandal. The players were looking forward to seeing lots of kids in the stadium and there were plenty of empty seats.
"There was something missing from what I wanted to see here and that was those 200 kids who could not come in," added Domenech.
The idea to come for the first time to the tropical French Indian Ocean island of Reunion, famous for its spectacular scenery with active volcanoes, luxuriant vegetation and wild beaches, came from Domenech.
TEAM BOND
The coach organised a trip to the French Caribbean island of Martinique in the build-up to the 2006 World Cup and the players said afterwards the warm welcome they received there had helped the team bond and go all the way to the Berlin final.
Domenech, aware his side have reached a depressing low after a string of dismal performances, felt coming to Reunion this time could only help.
"I wanted the players to feel the fans love them," he said.
The local supporters have been following the team around with enthusiasm but have been frustrated at times, notably when the players just waved at them but did not stop to sign autographs at the end of a mountain bike ride on Tuesday.
"I know what it means for the people here to welcome the France team," said winger Florent Malouda ahead of their final World Cup warm-up against China here on Friday.
"They will want to show us that they are genuine fans."
