British investigators are circumspect but experts and security officials say incident has hallmarks of Iranian intelligence

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From Golders Green, where four ambulances belonging to a Jewish charity were set alight in the early hours of Monday, a tangled trail probably leads across two continents to Tehran.

British investigators are circumspect. Speaking at an event on Monday evening, Mark Rowley, the head of the Metropolitan police, described a “very relevant and rolling threat” from Iran to the UK, and specifically to Jewish targets, but warned it was still too early to attribute the attack in north London to Tehran.

Others who are less bound by the imperatives of policing and politics are not so cautious. In interviews, experts, security officials and others all pointed to Iran, which has been linked to a series of very similar attacks in recent weeks that have all targeted Jewish sites around western Europe with relatively low-tech incendiary devices.