A critically injured man who was struck by a train in Levin has woken up and acknowledged his name is Alan.

Police have released photographs of the injured man as a "last resort" in an effort to identify him.

The name Alan was muttered by the man hit by a train in Levin on Friday night and may offer a clue to his identity.

Two investigations will begin today into last night's train crash in Melbourne which injured five people.

A commuter train ran a stop light during morning rush hour and collided head-on with another train in a Brussels suburb overnight.

Crash investigators will want to know how two Belgian commuter trains came to collide head on.