People could not believe their eyes as megastar Amitabh Bachchan, celebrating his 64th birthday Tuesday, got into stunt acts for his ongoing film 'Ek Ajnabee'.

"Bachchan did all the action scenes in my film 'Ek Ajnabee' on his own... no body double, no short cuts, just the actor and the danger zone, which he adopted unhesitatingly," says an amazed director Apoorva Lakhia.

From the sneak previews of "Ek Ajnabee", one thing emerges with stunning certainty - Bachchan has never hesitated to do action scenes on his own since his career making "Zanjeer" 32 years ago.

How did he do it?

"I don't know," said the disarmed director, barely seeming to believe what he saw.

"Bachchan saab refused to let anyone else do the action for him. Keeping his unbelievable energy level even at his age, we nevertheless took all precautions. For instance, I would shoot early morning with other members of the cast. Only then would Bachchan saab arrive on location all charged and raring to go. After that there was no stopping him."

Lakhia reiterates that these are no ordinary stunts.

"The action scenes are not your stylised choreographed pieces of fast-moving frames. These are all John Woo kind of action scenes done to highlight the survival instinct rather than macho aggression.

"This is a man who has to fight back to preserve his life. One thing I was sure of... I had to make my hero look exceptionally heroic.

"I mean you can't have Bachchan Saab as anything but larger-than-life. For me 'Khakee' was over when a subordinate slapped the super-cop. Come on, no one slaps Bachchan Saab and gets away with it!"

Speaking of his incredible stunts in "Ek Ajnabee", Bachchan says: "It's nothing really. It's the unique presentation that makes me look good in the action scenes. Why did I dare do them? That's a funny question! Why do I act? Why do I breathe!"

And for those who wonder where the awesome reserves of energy comes from, here is more news - the Big B was in Jaipur Thursday frantically trying to finish the shooting of Vinod Chopra's "Eklavya".

He shot through the night of Oct 5 till 5 a.m. The he shot through most of the day and all night before flying back to Mumbai on the morning of Oct 7. A couple of days later, he was flying again to join Karan Johar's unit of "Kabhi Alvidaa Na Kehna".

Now are you still wondering how Bachchan managed those heart-in-the-mouth stunts in "Ek Ajnabee"?