He was speaking after a security alert near the polling station in the Moss Park area last night.
ATO was called in to examine the object but later declared it an elaborate hoax.
When police officers attended the scene they came under attack with five petrol bombs being thrown at them.
One of the petrol bombs thrown was in the Glengalliagh Park area where there was a number of children in close proximity to where it landed.
Police later recovered six petrol bombs from the area, along with 20 paint bombs and two crates of empty bottles.
Officers subsequently arrested three male youths, two teenagers aged 17 and a boy aged 12 in connection with the disorder.
All three are currently in custody assisting with enquiries.
Police condemned the disord and a senior officer said police had been lured into the area to be attacked with petrol and paint bombs.
Said Cllr Tierney: “The SDLP pressed hard for St Paul’s to be included in the polling station scheme so that local people would have the opportunity to cast their vote nearby.
“We have now experienced two alerts in the middle of two consecutive elections.
“This has caused significant disruption for voters, electoral office staff and others in this community.
“If this does not stop, if the democratic process is not allowed to happen free from interruption, then there’s a real possibility that polling station scheme will be altered and local people may have to travel double the distance to cast their votes elsewhere.
“The only people who lose out in that scenario are those who live in our community.
“I am appealing for those involved in this to stop immediately.”