Detectives investigating a car bomb which exploded outside Strand Road police station in Londonderry have been given another extension to question a 54-year-old man about the attack.
He was arrested on Monday and police were given permission to detain him for four days. On Thursday, they were given permission to hold him for four more.
A 42-year-old man, arrested on Saturday, remains in custody.
The bomb, which was blamed on dissident republicans, exploded on 3 August.
No-one was hurt in the explosion.
A taxi was hijacked and packed with 200lbs of homemade explosives. The driver was ordered at gunpoint to leave the car at Strand Road police station.
An organisation calling itself Oglaigh na hEireann claimed it was behind the attack, which badly damaged a number of businesses at about 0320 BST.