A 37-year-old man has been arrested on suspicion of preparing terrorist acts following a string of attacks on Jewish sites across London.
He was arrested by counter-terror police at an address near Barnstaple in Devon on Sunday.
Twenty-six people have been arrested since late March over the series of attacks on Jewish sites, the Metropolitan Police said.
There have been arson attacks on Jewish community ambulances in Golders Green, north-west London, a synagogue and a former Jewish charity, as well as an incident where a drone was flown near the Israeli embassy.
Counter-terror police have been looking into the possible involvement of Iranian proxies.
Premises linked to people opposing the Iranian regime have also been targeted, the force said last week.
An attempted arson attack was also carried out on 15 April at Finchley Reform Synagogue, and outside the offices of a Persian media company, both in north-west London.
On Tuesday, a 17-year-old boy pleaded guilty at Westminster Magistrates’ Court to arson not endangering life following an attack on Kenton United Synagogue.
Speaking at the synagogue during a visit on Thursday afternoon, Sir Keir Starmer said: “We have to deal with malign state actors, that will require legislation.
“We’re going to bring that legislation forward.
“It’s really important we do that. It’s very important this particular context because I’m increasingly concerned that a number of countries are using proxies for attacks in this country.”
At a roundtable discussion with leaders of the Jewish community, including Chief Rabbi Sir Ephraim Mirvis and those local to the Kenton United Synagogue, the prime minister said the fight they face to practice their religion freely is “all of our fight”.
