BBC
A fourth man has been arrested over a series of fires connected to Prime Minister Sir Keir Starmer, the Metropolitan Police has said.
The 48-year-old was arrested on Monday at London's Stansted Airport after initially being stopped by officers under schedule 7 of the Terrorism Act, 2000.
He was later arrested on suspicion of conspiracy to commit arson with intent to endanger life.
The charges relate to three incidents - a vehicle fire in Kentish Town, north London, a fire at the prime minister's private home on the same street and a fire at an address that he previously lived in Islington, north London.
The man has been taken to a London police station and remains in custody.
Three men have already been charged in connection with the fires, Ukrainians Petro Pochynok, 34, and Roman Lavrynovych, 21, and Ukrainian-born Romanian national Stanislav Carpiuc, 26, who are all due to appear at the Old Bailey on Friday.
Lavrynovych, of Sydenham, is charged with three counts of arson with intent to endanger life.
Carpiuc, of Romford, and Pochynok, of north London, was charged with conspiracy to commit arson with intent to endanger life.
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