POLICE have warned that a robber who threatened shop staff with a dirty syringe could strike again.

Detectives are investigating a robbery at a York video shop in which the attacker made off with £80 cash.

He threatened a young male employee at Blockbusters, in Hull Road, with a syringe full of brown liquid and demanded that he "empty the till".

Detective Constable Lee Boyson, who is investigating the incident, said the robber could strike again. He said: "This is a very nasty attack which we are treating extremely seriously.

"We hope that the public will be able to help us identify this individual so we can make sure he is arrested and prevent anyone else going through this ordeal.

"It's unusual for a man of that age to have a full beard and his appearance is distinctive. We hope this will help members of the public identify him."

The robbery took place at the parade of shops near the junction of Hull Road and Melrosegate on Saturday, at about 10.55am.

Police said the attacker, who was aged about 20 and had a fully-grown beard, walked into the empty shop and approached the counter.

He then told the employee, who was a former security guard, to empty the till and produced a syringe from his right pocket.

The money was handed over and the robber left in the direction of Tang Hall Lane.

Police said the employee was not hurt, but was left shaken. The robber was in the shop for less than one minute.

The robber was described as white, 5ft 5in tall, of skinny build with brown "scruffy-looking" hair.

He wore a black, hooded jacket with a zip that went half-way down his chest. It did not have a logo on the front. He also wore black Adidas tracksuit trousers and a baseball cap.

Staff at the Blockbusters branch today declined to comment about the robbery. The company said: "Blockbuster's primary concern is the safety of its employees, customers and property."

Anyone who was near Blockbusters at the time of the robbery is asked to phone Det Con Boyson on 01904 669846 or Crimestoppers, for free and in confidence, on 0800 555 111.

Updated: 10:38 Wednesday, August 17, 2005