They say the pair, aged 23 and 37, were shot on Lower King Street at Caboolture, north of Brisbane, just after 5pm on Saturday.

The two men, from Burpengary, were declared dead after being taken to Caboolture Hospital.

Witnesses told police arriving on the scene they saw a man driving off in a Toyota Yaris.

A manhunt for the gunman ended shortly after 7pm when a 24-year-old suspect was apprehended at a service station 80km away, in Cornubia to Brisbane's southeast.

Police picked up a Toyota Yaris at the service station.

The three men were known to police and to each other, Detective Superintendent Ben Fadian told reporters on Sunday.

"This is not a random incident," Det Supt Fadian said. "The community should not feel concerned about their own safety as a result of this."

The alleged shooter lives at the unit block where the shooting occurred.

Police are still trying to establish a motive for the attack, and are calling for anyone who was in the area between 4.30pm and 5.30pm on Saturday to come forward, particularly if they have dashcam footage.

The 24-year-old Caboolture man has been charged with two counts of murder, possessing a shortened firearm and other weapons offences.

He is due to face Caboolture Magistrates Court on Monday.

Residents in the unit block have been locked out of their homes so police can investigate the crime scene. Det Supt Fadian said alternative accommodation had been arranged for residents.

Australian Associated Press