A group of Timaru shoppers have "courageously" intervened in a violent robbery in Timaru pharmacy today - detaining the thief until police arrived.

At about 10:30am today, a 51-year-old man allegedly attempted to rob the Marchwiel Pharmacy in Selwyn St, Timaru.

Police have praised the actions of several people in the pharmacy who apprehended the offender during the attempted robbery.

"The members of the public who came to the assistance of the frightened pharmacy staff acted courageously,'' Sergeant Kevin McErlain said.


"In general we don't encourage people to take unnecessary risks but we appreciate in this instance they acted instinctively to detain the offender until we got there."

A 51-year-old man was due to appear in the Timaru District Court today charged with aggravated robbery.

Police are also keen to talk to anyone who witnessed the robbery, particularly a man in a white ute who was involved in apprehending the offender, who they have not been able to contact.

Anyone with information can call Timaru Police on 03 684 9239 or the police non-emergency number on 105.