Sussex Police have arrested two further men in connection with the damage of post boxes and telephone kiosks in the Chichester district.
And now, a police spokesman has confirmed that a 22 and 23-year-old man both from Chichester have also been arrested on suspicion of causing explosions likely to endanger life or injure.
Eight postboxes and telephone kiosks were damaged in Bosham, Lavant, Charlton, East Dean and Oving, police said.
Detective Sergeant Vicky Guy said: “We have now made a total of five arrests but this still remains a live investigation
“We continue to appeal to the public and ask anyone with information to report it to us without delay.
“You can do this either online or by calling 101. Alternatively, you can visit the Crimestoppers website or contact the independent charity anonymously on 0800 555 111.”
The two men were released on police bail until February 8.