A 74-year-old woman was robbed in her flat at knifepoint after her attacker followed her home.

The pensioner handed over cash and a bank card.

She was followed after a shopping trip in St James's Street, Brighton, at 7pm yesterday.

Police say the woman heard a noise behind her as she opened the door to her basement flat.

She turned to see a man holding a kitchen knife who ordered her to go inside.

The offender then spent five to ten minutes inside with the woman before leaving with her bank card and an undisclosed sum of cash.

He made threats towards his victim but did not physically harm her.

Police spokeswoman Carolyn Bond said: "This was an extremely unusual incident. The elderly woman was caught completely unawares by this man. She is extremely shocked and distressed by what happened.

"The woman walked home from St James's Street via Portland Place and the man must have started following her somewhere in that area.

"We will be looking at CCTV footage, but there must also have been a lot of people in the area at that time, some of whom may have seen this man following the elderly woman."

The offender is described as 17 to 22 years old, white, 5ft 10in tall, slim and with short, spiky, mousy-brown hair. He had blue-green eyes, a fair complexion and a mild Scottish accent.

Detective Sergeant Chris Standard said: "We're treating this very seriously and have a good description of the offender."