OAKLAND (CBS SF) — Six men in their 20s and 30s were wounded early Saturday when gunfire erupted in the Old Oakland district near police headquarters.

The San Jose Mercury News reported that all six were in stable condition at local hospitals and expected to recover from their injuries.

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ShotSpotter was triggered several times around 1:05 a.m. in the 900 and 1000 blocks of Washington St in the popular nightlife area.

Authorities told the paper that they suspected that at least two gunmen may be involved. There was no immediate information released as to suspect descriptions or a motive.

Two businesses and at least three parked vehicles were also hit by the gunfire.

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Investigators said the wounded men were not cooperating. They were also trying to track down any surveillance video that may have captured images of the incident.

Police spokeswoman Officer Johnna Watson said “an officer was already nearby when the shooting occurred and was able to quickly respond to the area and secure the scene, call for additional resources and get key information for the investigation.”

The Oakland Police Department‘s Felony Assault Unit is actively investigating this case. Anyone with information is encouraged to call Oakland Police Department Felony Assault Unit at (510) 238-3426.

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CrimeStoppers of Oakland and the Oakland Police Department are offering a reward of up to $30,000 for an arrest in this case. CrimeStopper Tip Line (510) 777-8572