A 14-year-old boy has been arrested on suspicion of mugging a doctor who was on his way to work.
The victim was approached by three people and forced to withdraw money from a cash machine in Harlow, Essex, on Wednesday night.
He had been on his way to a hospital when he was approached in Market Square at about 21:25 GMT, police said.
Officers believe the attack may be linked with two further robbery attempts within the following hour.
A second victim, approached outside a McDonald's restaurant at 21:50, fled after a group asked for a cigarette and money.
A third victim was approached in Fifth Avenue shortly after 22:15 but escaped unharmed after three people threatened to stab him.
The 14-year-old boy was arrested on suspicion of robbery on Thursday morning. Essex Police is trying to trace two other suspects.
It comes as a national salute is set to take place to honour the hardworking NHS staff who are trying to battle the coronavirus pandemic.