British police arrested a 21-year-old man early Tuesday over suspected arson attacks on two properties linked to UK Prime Minister Keir Starmer.
London's Metropolitan Police force said the man was arrested "on suspicion of arson with intent to endanger life".
He was being held in custody, the force added.
Emergency services were called to a blaze at the door of Starmer's former family home in Kentish Town, north London, at 1:35 a.m. (0035 GMT) on Monday.
"Officers attended the scene. Damage was caused to the property's entrance, nobody was hurt," the police said in a statement.
According to the BBC, the prime minister, who has lived in Downing Street since his Labour party won last July's general election, still owns the house and rents it out.
Police have linked the incident to a separate fire on Sunday at another property in north London -- a house converted into flats that British media have also linked to Starmer.
One person was assisted to safety via an internal staircase by crews wearing breathing apparatus, according to the London Fire Brigade.
Police were also probing a vehicle fire on May 8 as part of their investigation.
The force's Counter Terrorism Command was leading the investigation due to Starmer's high profile.
"All three fires are being treated as suspicious at this time, and enquiries remain ongoing," the police said.
On Monday, Starmer's official spokesman said: "The prime minister thanks the emergency services for their work, and it is subject to a live investigation. So, I can't comment further."