An elderly widow had her handbag snatched while she was cleaning her late husband's grave on Christmas Eve, police said.
The 73-year-old woman was approached from behind and pushed to the ground in Hanwell Cemetery in west London.
A Metropolitan Police spokesman said: "After stealing the handbag, the suspect left the cemetery at 13.32hrs, walking off briskly towards Church Road whilst covering his face."
The bag was recovered by a member of the public but the woman's purse was missing. She suffered minor injuries.
Police described the thief as a skinny man of about 5ft 9in. He was wearing a black scarf covering his face, a grey hooded top, a black coat and jeans.
The spokesman added: "The robbery took place in broad daylight and police are keen to speak to members of the public who saw a man matching this description walking briskly away from the scene, with his face covered and hood up."
Anyone with information was urged to call Ealing police via 101.