MILAN (Reuters) - Four Germans were killed in a mid-air collision between a helicopter and a light aircraft in the Italian Alps on Friday with the other three victims were from Italy, France and Belgium, Italian police said on Sunday.

“We can’t reveal the names because some of the families still don’t know,” one official at the joint office of Alpine rescue and police in Entreves, in the Aosta Valley, told Reuters.

The two survivors were a Frenchman and a German, the official said. The French survivor was under investigation in connection with the accident, he added, without giving any further details.

The German Foreign Ministry said officials at its consulate in Milan were working closely with Italian authorities to confirm the identity of the victims.

The two aircraft collided in mid-air above the Rutor glacier in the Aosta Valley, some 80 km (50 miles) northwest of the city of Turin on Friday afternoon.

The Italian rescue workers had found five of the victims and the two survivors on Friday. Two more bodies were discovered in the snow some distance from the wreckage of the two aircraft on Saturday.

It is not yet clear how the accident happened.