The band have issued a statement.

Sum 41 have been forced to cancel a show in Paris this evening (January 18) after an explosive device was detonated near the venue.
Thankfully, nobody was injured, and the band have taken the decision to cancel the show, posting a statement on social media:
“During load in for tonight’s performance in Paris, an explosive device was detonated just outside of the venue door. Band, crew, the fans in line are all safe, and there were no injuries. Due to the intimate nature of our ‘Personal Space’ performances, we are unable to guarantee the safety of the fans in attendance. We are deeply saddened to announce that tonight’s show has been canceled. More information to follow.”
Refunds are available by contacting Live Nation at the point of purchase.
Read the band’s full statement below: