Nottingham Express Transit are investigating the partial derailment of one of their trams in the Basford area of the city. The tram was damaged on Sunday when it came off the track during testing.
Stephen Barker from NET insisted there is no need for local people to be alarmed.
He said: "Trams are test running quite a lot of the time at the moment and what has happened is unfortunate - it's what we call a minor non-injury derailment.
Safety tests
"It's too early to say exactly what's happened but it looks more like a local problem than a serious safety issue.
"But safety is our paramount concern and there will be an investigation over the next few days .
"We will work out what went wrong and put it right.
"But I don't think there is any reason for people to be worried at all."