G20 training flights ramp up over Brisbane

Military aircraft will be criss-crossing the skies over Brisbane ahead of this weekend's summit of world leaders.

Australian Defence Force aircraft operating from Amberley RAAF Base will carry out training flights over the city on Tuesday and Wednesday to familiarise themselves with special airspace arrangements for the G20.

But unlike other recent exercises, there won't be any night flights.

"The training will practise a range of scenarios relevant to the security of a major public event," the ADF said in a statement on Monday.

Queensland Police Assistant Commissioner Katarina Carroll has repeated her warning that anyone contemplating violent protests should think again.

She said police would not accept damage to infrastructure or any behaviour that threatened public safety.

"What I don't want is an outbreak of a violent protest that will tarnish the city and leave it with a terrible legacy," she told Fairfax radio.

Ms Carroll also revealed the vast network of security cameras that will follow the every move of world leaders, and be used to monitor activities across the city, could become a permanent fixture.

She said the police operations centre, where 150 police will be monitoring security camera feeds from across the city, was built with the future in mind.

"There is a vast network of cameras, from the airport, right into the city and over to South Bank and the convention centre.

"Yes we hope to maintain that," she said.

Ms Carroll also said mobile phones should not be affected by any decision by visiting nations to scramble signals as 35 motorcades carrying world leaders move around the city.

"That should not be an issue. There are technologies those countries can employ, for themselves, but they should not be impacting on our use of technology."

She said police were continuing to work closely with the 27 known groups planning peaceful protests on the sidelines of the G20.

"We want people to be peaceful and lawful in their protests," she said.