Sheffield showed its solidarity with twin city Pittsburgh after a gunman entered a synagogue and opened fire, killing 11 people.
Councillors and members of the public gathered in the Peace Gardens on Monday for a vigil and service of remembrance.
Sheffield Council deputy leader Coun Olivia Blake was among those who gave a speech.
Six people were injured, among them four police officers, in the attack on the synagogue in the Squirrel Hill district.
The suspect, who was taken into custody, has been named as Robert Bowers, 46.
He entered the building shortly before 10am on Saturday, during a service.
He was armed with three Glock handguns and an AR-15 assault rifle.
He was leaving the building when he was met by emergency responders.
Two officers - among the first to arrive - were injured in an initial confrontation with the gunman.
A further two Swat team members were hurt inside the building, clashing with the shooter.
The gunman suffered multiple gunshot wounds and surrendered to the authorities.
The crime scene was described as ‘horrific by Pittsburgh's Public Safety Director Wendell Hissrich.