The British police said the attack on Wednesday was being treated as terrorism, and they warned of rising antisemitic hate crimes.

Officials are investigating similar attacks across Europe, all claimed by a shadowy Islamist group that may be using low-cost, unsophisticated methods to sow fear in Jewish communities.

Two men who were stabbed in Golders Green on Wednesday were in stable condition, the police said. One man was arrested on suspicion of attempted murder.

Iran’s embassy in London posted a message on social media inviting Iranians living in Britain to register for a ‘Sacrifice for the Homeland’ campaign.

The British royals are set to arrive on Monday for a visit hosted by President Trump, with a garden party, an address to Congress and a banquet on the schedule.