Emraan Hashmi, who had taken a break from work for his son, Ayaan's medical treatment in Canada is back in Mumbai.

The actor began shooting for Vikram Bhatt's 'Mr X' on Sunday. Says Bhatt, `Emraan is a strong guy and is holding up. Ayaan is much better.''

'Mr X' is a remake of Nanabhai Bhatt's yesteryear flick 'Mr X' that starred Ashok Kumar. 'Issaq' actress Amyra Dastur has been cast opposite Emraan.