March 25 (UPI) — British counter-terrorism police made two arrests early Wednesday in connection with an arson attack that destroyed four Jewish volunteer ambulances parked outside a synagogue in London.

The men, aged 47 and 45, were arrested in dawn raids at addresses in northwest London and central London on suspicion of arson with intent to endanger life and taken to a London police station, where they are being held in custody, the Metropolitan Police said in a news release.

The Met said it was continuing to work to identify another suspect, one of three captured on CCTV pouring accelerant onto the ambulances in the Golders Green area of north London before igniting it in the early hours of Monday.

The fires caused oxygen cylinders inside the vehicles to explode, shattering windows in nearby residential properties and forcing the evacuation of at least 34 people, but no one was injured.

Calling it an “appalling attack,” Commander Helen Flanagan, Head of Counter Terrorism Policing London, said officers had been working the case around the clock.

“This appears to be an important breakthrough in the investigation, but we’re also mindful that CCTV footage of the incident suggests there were at least three people involved. We fully recognise the local community will still be concerned and our investigation very much remains active and we will continue to work to identify and seek to arrest all of those who may have been involved,” Flanagan said.

More than 260 additional police officers, backed by firearms teams, have been deployed on the streets of Golders Greens and other areas of London with sizable Jewish populations to provide protection and reassurance to those communities.

Police do not routinely carry guns in the United Kingdom.

“We know that community concerns remain heightened and I want to reassure the community that an enhanced, bespoke policing plan and activity, which is particularly focused around vulnerable areas right across London, will continue over coming days and weeks,” said Detective Chief Superintendent Luke Williams.

“This includes specialist officers and capability being deployed alongside local officers to help protect certain locations and will also involve highly visible armed police patrols to serve as a deterrent to anyone seeking to cause our communities harm. I must stress that these are precautionary and not in response to any specific threat, and we continue to work alongside our colleagues in Counter Terrorism policing to support their investigation,” added Williams who is responsible for policing north west London.

The incident is being treated as an anti-Semitic hate crime, not terrorism, but the Met is investigating a claim made online by an Iranian-linked Islamist group that it carried out the attack.

Speaking during a visit to Washington on Monday, Met Commissioner Sir Mark Rowley warned of what he said was the “rapid growth” of threats from the Iranian regime but said it was “too early” to place the blame on Tehran.

Sir Mark said police were pursuing several leads, including “an online claim of responsibility by an Islamist group who have claimed other attacks across Europe and have potential Iranian state links.”

The ambulances belonged to Hatzola Trust, a non-profit volunteer-run Jewish community group providing first responder medical care and hospital transportation free of charge to residents of north London of all religions.

Hatzola works alongside about 2,000 ambulances and support vehicles operated by the London Ambulance Service which is part of the free National Health Service.