A gunman is on the run after shooting a teenager in the leg in bushland at Kingston, south of Brisbane.

The 19-year-old victim was treated for the single gunshot wound and taken to hospital in a stable condition, the Queensland Ambulance Service said.

The Kingston State College, which is 2.5 kilometres away, was placed in lockdown as a precaution but the measure was lifted just after midday.

A police helicopter and dozens of officers are searching for the shooter.

Local Janina Poona said a friend of the victim came running from the bush to her house, banging on her side door.

"He was yelling 'somebody help me, somebody help me, someone has been shot'," she said.

"He said he was dying and needed help."

Ms Poona rang triple-0 but resisted the man's request to go to the shooting victim to help him.

"He was calling us down and I didn't want to go down," she said, adding that she had not heard the gunshot.

"You don't want to go down, you don't know who he is and what had happened."

Police photograph the crime scene, after the teenager was shot about 10:00am. ( ABC News: Elizabeth Pickering )

Steven Asanuma said he too could not bring himself to enter the bush.

"He [the friend] didn't know what to do about his mate being shot in the leg and was a bit worried," he said.

"He asked me to help him.

"I said I would come over a bit later, when the coast was clear.

"I haven't made it over yet."

The PolAir police helicopter has joined officers on the ground for the search. ( ABC News: Elizabeth Pickering )

It is the second police emergency in the street this year.

In February, two bodies were found in a dam off Mudgee Street.

"There is a lot of vacant land," Ms Poona said.

"That seems to be calling the problems here.

"How do you think I feel? I'm extremely worried."

Police cordon off an area in their search for the gunman. ( ABC News: Josh Bavas )