A number of people have been evacuated from their homes following the discovery of a suspicious object at the flyover.
Chief Inspector Alan Hutton said: “Police are dealing with a security alert close to the Lecky Road flyover in Derry/Londonderry.
“A cordon has been put in place and a number of houses in the area have had to be evacuated while the security operation continues.
“We are doing everything we can to minimise the impact to the community but are grateful for the patience of the local residents and wider community.
"Police will be working as quickly as possible to ensure everyone’s safety."
Sinn Féin councillor Colly Kelly said: “Whoever left this device has only succeeded in causing hardship to the local population.
"It’s very upsetting for many of the elderly residents and those with young families caught up with all this disruption.
"It is obvious that the those behind leaving such devices are out of touch with the will of the vast majority of the people of the Bogside who want to move forward without this type of disruption."
The SDLP leader Colum Eastwood said: “It is absolutely disgraceful that a suspect device has been placed right in the heart of our community. Those responsible must be stopped.
“Residents are now being evacuated from their homes on a cold Sunday afternoon thanks to those behind this attack on our community.
"Those responsible achieve nothing from their actions, instead their big victory is frightening and causing disruption to local people. They need to catch themselves on.
“The SDLP is working closely with the PSNI to ensure the safety of all in the area. I urge anyone with any information to bring it forward immediately to the authorities.
"There’s only one way to stop these attacks, that is for all of in our community to unite and speak out against those who seek to drag us back to the past.”