Police are appealing for information from the public after a teenager was shot four times in the back and is in a critical but stable condition in hospital.

The man, 19, presented to Southland Hospital with four gunshot wounds to his back about 4.40pm on Saturday.

He has undergone surgery and remains in a critical but stable condition in hospital.

As part of their investigations, police conducted a search warrant at a Tweed St address where the incident is believed to have occurred.

A number of items of interest were found and officers remain at the address.

Invercargill police Detective Sergeant Mark McCloy said it was believed the incident could be gang-related.

While discussions with the victim have been conducted, McCloy encouraged anyone with relevant information to inform police.

"If you saw anything unusual or suspicious in the area of the eastern end of Tweed St on Saturday afternoon, around 4-5pm, please get in touch with police on 105 and quote file number 211003/3406," he said.

Information can also be provided to Crime Stoppers anonymously on 0800 555 111.

McColy wanted to reassure the community that police were "hugely focused" on locating those responsible.