Penshaw Monument has been lit up red, white and blue tonight as Sunderland stands shoulder-to-shoulder with the people of Manchester.
The monument and the Magistrates' Court building in Keel Square will both be lit in the colours of the Union flag until Sunday.
At Sunderland Civic Centre,the Union flag is being flown at half mast as a mark of respect to all those who were killed and injured in last night's terrorist attack.
City council leader Coun Paul Watson said: "This was a dreadful attack which is all the more sickening because it was targeted at innocent children and young people.
"Our thoughts and our prayers go out to all those caught up in this devastating tragedy and their family and friends.
"It is right and fitting that as a city we show solidarity with the people of Manchester as they come to terms with this cowardly assault.
"It's important too that we pay tribute to the emergency services who worked so tirelessly to rescue and treat those who were caught up in the attack.
"I'd like to salute the people of Manchester who have shown such an inspiring community spirit in the face of this act of terrorism and I know the people of Sunderland will join me in sending our sympathies to them."