“Our thoughts are with André’s relatives, who we also want to support during this difficult time,” the fire department’s statement said.

The Lower Saxony youth fire brigade also paid tribute to the nine-year-old.

“Our condolences go out to his family, his friends and everyone who was close to him,” it said in a statement.

“We stand by their side in these difficult times and express our deepest sympathy,” it added.

The attack on Friday left more than 200 people injured, with some left in a critical condition.

The four women who were also killed have not yet been identified.