Football players escaped serious injury when a flare or firework was thrown on to one of Dundee United’s training pitches.
Players using the GA Engineering Arena on Sunday had their game interrupted when a passerby threw the item on to one of the all-weather pitches around 9pm.
No one was hurt in the incident.
The centrepiece of the training centre, formerly known as Gussie Park, is a state-of-the-art 3G training pitch which has a two-star rating from Fifa.
It is mostly used for youth training and by the community, although the Tannadice club’s senior squad occasionally train there.
One concerned mum said: “My son said police were called to another game there as someone threw a water bottle at the ref then someone threw a flare on to the pitch.
“He said he didn’t see anyone getting taken away.”
A spokesman for Dundee United said: “We can confirm a flare was thrown from the street outside into the GA Arena on Sunday night.
“Thankfully, no one was injured and Police Scotland were notified of the incident.”
The £300,000 redeveloped facility was officially opened in March.
Rooms at the centre have been named in honour of previous successes of the United youth system, including Christian Dailly, Duncan Ferguson and Ryan Gauld.
Football fans have been fined for throwing flares on to pitches during matches.
Dundee United fan Ryan Mulholland was fined £1,000 for throwing a flare on to the pitch during a match against Stranraer in February.