A gang of men attacked and robbed two women in 20 minutes.
The thieves first approached a 65-year-old woman from Shoreham in the Aldi car park in Carlton Terrace, Portslade, as she walked towards the store at about midday on Tuesday.
One said hello to the woman while a second punched her in the face and knocked her over.
They took her purse and ran away.
About 20 minutes later a 25-year-old woman walking in Poplar Avenue, Hove, was hit by a moped that was deliberately driven at her.
The three young men then demanded she give them her handbag.
She refused and they fled with the moped before putting it into the back of a white van and driving away
The woman, from Hove, suffered cuts and bruises and the Portslade victim was shaken and bruised.
The first man was about 5' 6" and blonde. He was wearing a cream hooded top and light trainers. The other two men were 5' 8" and had dark hair.
Detective Sergeant Cheryl Lewendon said: "The men were all white and have been described as being teenagers or in their early twenties.
"We urgently need to find them.
"These were brazen attacks in the middle of the day in areas where the attackers could have been seen by many people passing by.
"If you know who they are or where they could be, please contact us.
"Anyone with information should call 101 quoting serial 543 of 25/3, email email@example.com or call the independent charity Crimestoppers anonymously on 0800 555111."