What is the name of the movie?

I watched a movie in my childhood about 15 years ago i dont know the name and remember anything except some glimpses . one of the scenes is that allied forces are traveling in a train. An undercover german officer (in uniform of lower rank officer but infact a high rank officer) pretending as belonging to allied forces is also with them.. at one station the gestapo agent get off the train where there are many german soldiers. the agent introduce himself to the soldier and soldier salutes him. The undercover soldier asks german soldiers to arrest the allied forces soldiers in the train. allied forces’ soldier see this and understood that he is an spy. In the mean time the train starts to move and allied forces are saved from being captured. can somebody tell me the name of the movie i desperately wish to watch that movie again.