Foyleside was evacuated after police received reports of a bomb in the building.
Councillor Tierney said the incident was causing serious disruption in Derry city centre on Tuesday.
Said Cllr Tierney: “As a result of this security alert all shoppers and staff had to be evacuated from Foyleside Shopping Centre on Tuesday afternoon.
“Members of the public just going about their day and people trying to earn a living were forced out of the centre as businesses were forced to close their doors.
“Our businesses have been through a hard-enough time over the past few years without being forced to close as a result of a bomb threat.
“While this alert is ongoing these businesses will be losing out on much-needed revenue and it’s another kick in the teeth for people who are trying to keep their heads above water and provide services to people here.
“This is the last thing we want to see in our city, this is the second security alert today, following one in the Hawkin Street area on Tuesday morning.
“These incidents achieve nothing other than causing disruption to our communities and I would urge those behind them to cease this type of senseless activity at once.
“I’d encourage anyone with any information about either alert to come forward to police as soon as possible.”