Police forensic teams are combing Hoani Street after four people were injured, including one critically and one seriously, in what police said was a targeted gang related altercation overnight.

Emergency services were called to the Northcote property about 9:30 pm following reports of an altercation between 2 parties.

On Thursday afternoon police confirmed a firearm was discharged during the incident.

Detective Inspector Nicola Reeves said police were following strong lines of enquiry as staff examined the scene and gathered information about those involved.

Reeves said four people were injured, with two remaining in hospital.

Police said the incident was gang related and targeted towards parties at the address.

Reeves said while incidents like this can be unsettling for residents, police did not believe there was any risk to the wider public and additional patrols would be visible in the area as enquiries continue.

Canterbury Police District Commander Superintendent Tony Hill said police were doing all they could to locate the offenders.

Hoani Street remains cordoned off with a large police presence, including a mobile command unit and a police tent erected outside the property where the incident happened.

Police are urging anyone with information to call 105 and reference 260218/3391, or provide information anonymously through Crime Stoppers on 0800 555 111.