Mumbai, Jun 7 (IANS):  Actors Varun Dhawan and Sikandar Kher are pushing the envelope for intense action training for the upcoming Indian remake of 'Citadel'.

Varun and Sikandar have started prep work to perform these sequences. According to a source close to the production, the actors are currently taking training to prepare for action sequences.

According to a source close to production: "The series is going to have high-intense action and it being a spy series there has to be a particular swiftness in the movements and fight sequences, for which the training is currently underway. Shoot will continue till July for the series."

The series also stars Samantha Ruth Prabhu. Helmed by 'The Family Man' creators Raj and DK, 'Citadel' is the Indian counterpart of the larger international series of the same name which has been originally created by the director duo, Russo Brothers.

The global version of the series stars Priyanka Chopra Jonas and Richard Madden.