Petrol bombs were thrown at police responding to a number of security alerts in the city on Wednesday, the force have confirmed.
It's the fifth consecutive night fire bombs have been hurled at officers in the city.
Assistant Chief Constable Alan Todd said: “No part of this is acceptable and today we are looking at the evidential picture to pursue lines of enquiry.
“I would like to pay tribute to the job that my officers, along with other emergency services, did last night.
“The disorder we have seen has been caused by a small minority of people who have no regard for their communities. No one wants to see disruption and disorder and the people behind these incidents need to ask themselves just what they are achieving."
Referring to today's Twelfth of July parade, which will see thousands of Orangemen descend on Derry for the loyal order's main County Derry demonstration, he said: “I sincerely hope that today passes off peacefully and that the thousands of people who are attending community events and parades can do so enjoyably and safely.
“I would ask all of those with influence to work with us to ensure the safety of all.
“Our priority remains, keeping people safe and I want to reassure people this morning that our response, should there be an further disorder, will continue to be proportionate with the necessary resources in place to detect and deter those responsible.”