It's said to have happened on Sidwell Street on Monday 15 July.
A woman was approached by another woman who took her phone and then punched in the nose at around 11pm.
Officers have issued a picture of a woman they wish to speak to as part of their investigation.
Rocket builder careers in Cornwall to soar
'Twas the weather warning before Christmas
Police watchdog investigates after fatal Plymouth crash
Torbay memorial bench prices top London's
There’s No Place Like an Exeter Panto
Festive fanatic launches 'one song' Christmas station
