A 69-year-old was dragged to the ground and suffered cuts and bruises when a robber grabbed her handbag.
And police are warning people to be wary of walking in alleyways and secluded areas on their own until the culprit is caught.
The woman was walking in Bramber Lane, close to Coldstream House, at about 1.15pm on Monday (February 10) when a man approached her from behind and grabbed her bag.
The bag, described as tan or cream, was pulled with such force that the victim fell and suffered cuts and bruises.
The thief, described as a young man in dark clothing, escaped towards the Crouch.
Police are keen to speak to anyone who was in the area at the time, especially if they saw anyone suspicious then or in the minutes beforehand.
The bag has been recovered but some items are still missing.
Sergeant Stuart Mullins said, “This was a nasty incident and is being treated as a robbery.
“Offences of this sort are rare in Seaford and we are very keen to find the person responsible. Until then I would urge the public to be wary of walking along alleyways or secluded routes on their own.
“We are also asking that anyone with any information come forward especially if you think you might have seen the attacker or know who it is.”
Anyone with information should call 101 quoting serial 629 of 10/2, email firstname.lastname@example.org or call the independent charity Crimestoppers anonymously on 0800 555111.