The buzz on the young doctor’s phone alerted him to his new patients. But this appointment, arranged via an encrypted messaging app, was no normal one at his Hong Kong government hospital.

After he finished his regular evening shift, the doctor set off for the rendezvous — a hotel room in Kowloon.

He had to walk the final stretch because some roads were closed to traffic by the police siege of Hong Kong Polytechnic University, scene of the most violent clashes in the territory’s six-month turmoil. Waiting to see him were two students who had made it out of the encircled campus in a daring “Great Escape” as protesters abseiled down ropes from a flyover to be whisked away by waiting motorbikes.

The Polytechnic University has seen the most violent clashes GONZALEZ PHOTO/ALAMY LIVE NEWS

The pair, a