A TERRIFIED assistant had to lock herself in a back room after she was chased by a knifeman who burst into a shop in York today screaming abuse.

The man had been seen acting suspiciously in Martin's newsagents, in Hamilton Drive, Acomb, shortly before the incident.

He had left the shop, but police said he returned at about 6am and started screaming abuse and threatening staff.

He then pulled out a knife with a six-inch blade and chased the shop assistant, who escaped into a back room and locked herself inside.

A man was arrested in connection with the incident and was today being questioned at York police station.

Updated: 15:08 Thursday, April 18, 2002