The ninja sword ban is the final part of the so-called Ronan’s law, a raft of anti-knife crime measures introduced in parliament last month as part of the government’s crime and policing bill.

Brits have until Aug. 1 to get rid of all their ninja swords as the U.K.’s Labour government looks to crack down on knife crime. U.K. Prime Minister Keir Starmer announced Thursday that “ninja swords” ...