Police in Londonderry have carried out searches as part of the investigation into Tuesday's car bomb attack.
The security operation took place on Thursday night at Hatmore Park in the cityside. There were no arrests.
A taxi filled with 200lbs of homemade explosives was driven to Strand Road police station where it detonated at about 0320 BST on Tuesday.
No one was injured in the attack, but a number of businesses were badly damaged.
An organisation calling itself Oglaigh na hEireann has claimed it was behind the bomb attack.