An 18-year-old police constable was robbed of two gold chains valued at about $600,000 by a masked gunman at Britton Street, Plaisance, East Coast Demerara, on Tuesday night.

Police in Regional Division 4C said the robbery under arms occurred about 10:15pm. Preliminary investigations indicate the constable was socialising with friends when a masked male armed with a handgun approached him.

The gunman reportedly snatched the chains, which weighed a combined 68 pennyweights, from the constable's neck and fled towards the eastern side of the street. Several loud explosions suspected to be gunshots were then heard, causing the constable and his friends to disperse.

Police said the suspect entered a waiting silver car, which headed north along the roadway.

Investigators are reviewing CCTV footage from the surrounding area. No arrests have been made.