London police have arrested a second suspect in arson attacks targeting UK Prime Minister Keir Starmer's properties, following earlier charges against three Ukrainians.

Authorities have arrested a second suspect in connection with a series of arson attacks targeting properties associated with UK Prime Minister Keir Starmer, the police announced on Saturday.

A 26-year-old man was taken into custody at Luton Airport on suspicion of conspiracy to commit arson with the intent to endanger life.

This arrest follows the court appearance of three Ukrainian men on Friday, who face charges of setting fire to Starmer's personal residence, as well as to a property he previously lived in and a car he had sold. The police have not disclosed the nationality of the second suspect.

No injuries were reported from the fires that occurred over three nights in North London between May 8 and May 12.

Roman Lafrenovych, 21, did not enter a plea on Friday at Westminster Magistrates' Court regarding three counts of arson with intent to endanger life.

The prosecutor stated that Lafrenovych denied igniting the fires, and currently, there is no explanation for the incidents.

Starmer and his family relocated from their home following his election in July and are now residing at the official Prime Minister's residence at Downing Street.

The Toyota RAV4 formerly owned by Starmer was targeted on May 8, just down the street from his house. On Sunday, arson was reported at a residential building where the politician once lived. On Monday, the entrance to Starmer’s home was also set ablaze.

The investigation is being led by counter-terrorism officers due to the involvement of the Prime Minister. The Crown Prosecution Service’s counter-terrorism division, responsible for prosecuting crimes pertaining to national threats, has authorized these charges.

Starmer and leaders across the House of Commons condemned the fires earlier this week, with Starmer describing the incidents as "an attack on all of us, on the democracy and values we stand for."