Mumbai, Jun 2 (IANS): Megastar Amitabh Bachchan has started prepping for the next schedule of the upcoming film "Brahmastra" along with co-actors Ranbir Kapoor and Alia Bhatt.

Amitabh late on Friday took to Twitter and Instagram, where he shared a few photographs of himself with Ranbir, Alia and the film's director Ayan Mukerji.

"We prep for 'Brahmastra'. Ayan , Ranbir , Alia all except moi. I propagate brushing teeth," Amitabh captioned the image.

Alia took to her Instagram stories, where the trio is sitting with Ayan.

"When you're day begins with prep with Amitabh Bachchan," she captioned the image.

The cine icon, 75, also wrote on his blog about starting the prep for the next schedule.

"But before that, there is that small matter of ‘Brahmastra', the next film on line starting in a couple... and the look and feel tests and the introduction to texts of the script, and the prep for the readings among the three of us -- Alia, Ranbir and Ayan...," he wrote.

He added: "It is a routine that never existed in my time but the thoroughness of preparation and detailing of every aspect in the making is quite quite remarkable."

This will be the first time that Amitabh, Ranbir and Alia will be joining hands for a project. The trilogy's first part will release on Independence Day, August 15, 2019.

The "Piku" star also added that he is also prepping for his next with filmmaker Sujoy Ghosh, whom he calls a "mad Bong".

"Alongside goes the prep and looks for the next after... also in a few for Sujoy Ghosh, the absolutely mad Bong... but a delightful company! Will be my second as a director and a production done earlier. All to be shot in regions away from the shores of the land...

The two have previously worked in films like "TE3N", "Kahaani" and "Aladin".