Police search for specific witness in south Belfast security alert probe

Police are making a specific witness appeal as they continue to investigate a security alert on Friday in south Belfast.

It's after an object was thrown through the window of a building on University Road and a device left inside.

It was later found to be viable.

A 34 year old man was arrested - officers wish to speak to a young man, possibly in his 20s - who intervened and apprehended the suspect until police arrived.