The men were arrested on suspicion of conspiracy to commit arson with intent at separate addresses in east London on Wednesday.
Three more people have been arrested after four Jewish community ambulances were targeted in an alleged arson attack in north-west London.
Two British men, aged 19 and 20, and a 17-year-old dual British-Pakistani national, were arrested at separate addresses in east London on Wednesday.
They were all held on suspicion of conspiracy to commit arson with intent to endanger life and their homes are being searched.
Four ambulances from Hatzola, a volunteer-led ambulance service operating in the Golders Green area of north-west London, were set on fire in the early hours of March 23, causing gas canisters stored in the vehicles to explode.
Prime Minister Sir Keir Starmer called for communities to “all stand together” in the face of the “horrific antisemitic attack”, while Chief Rabbi Ephraim Mirvis said the targeting of the volunteer service was “particularly sickening”.
