May 20 (UPI) -- Authorities in Britain have arrested a third suspect in connection with a fire set at a home owned by Prime Minister Keir Starmer.

The unidentified 34-year-old was arrested Monday morning in Chelsea on suspicion of conspiracy to commit arson with intent to endanger life, Metropolitan Police said in a statement.

The arrest comes after a 26-year-old was arrested Saturday and a 21-year-old was arrested May 13.

The 21-year-old suspect has since been identified as Ukrainian national Roman Lavrynovych, of Sydenham, London.

The Crown Prosecution Service on Thursday authorized Lavrynovych to be charged with three counts of conspiracy to commit arson with intent to endanger life.