Detectives are trying to establish what caused the explosion.

It is understood one of the lines of enquiry they are following is that it was an under-car booby trap device.

The incident happened in the Dunclug Park area of the town at 1440 BST on Friday.

The young officer, who had only recently completed his training, was getting into his vehicle when the explosion happened.

The area was cordoned off after the explosion and Army bomb experts were called to the scene.

A police service spokesman said the officer was off duty at the time.

A DUP assembly member for the area said he was alarmed at the incident.

"Obviously we need to establish what exactly happened but this is a very worrying development," said Ian Paisley jnr, who is a member of the Northern Ireland Policing Board.