Fans were left frustrated with the US comedian's strict policy as some claimed they were removed from the venue for as little as sending a text.

But others saw the funny side as they reported sightings of so-called "cell phone security" around the O2 Arena on Sunday.

And one person keen to share a snap of their experience on social media was forced to resort to more primitive means.

It is not the first time phones have been banned at gigs - but it might be the dawning of a new age of enforcement.

Chris Rock fans will recall a similar ban as they were forced to keep their mobile phones in a locked pouch while at his shows last year.

But Hart's ban does not include any such technology - instead relying on so-called "cell phone security" to police the venue and enforce the rule.

Fans were warned in advance of the ban, which has applied to Hart's entire UK tour.

O2 advised attendees that "anyone caught using a phone or camera before or during the show will be ejected with no refund", with the other tour venues issuing similar warnings.

And one fan shared a picture of a leaflet apparently handed out at the show reinforcing the rules.