A gun attack outside the Co-op on Chapel Street, Woodhouse, on Monday was the third shooting in the city in the space of five days.
A car was shot at and three men jumped into the vehicle and sped off from the scene.
Dertectives are working on the assumption that there was somebody in the grey-silver estate at the time of the shooting, but as of last night the victim had not been identified.
Last Friday, a car was shot at in Raby Street, Tinsley and last Wednesday a 39-year-old man was shot at twice as he got out of his car in Malton Street, Pitsmoor.
When asked whether the three shootings were linked, South Yorkshire Police said: “Not that we’re aware of.”
The force added: “We are keeping an open mind as to whether this could be linked to any other incidents but at this time we believe it to be a standalone incident.”
The shooting is believed to have been a ‘targeted’ attack, the force added.
Yesterday, five men and a woman were in police custody on suspicion of possession of a firearm with intent to cause fear or violence.
Anyone with information should call South Yorkshire Police 101 or Crimestoppers, anonymously, on 0800 555111 and quote incident number 843 of September 30.