Hundreds of cameras will be scanning Brisbane for the next week as world leaders roll into town for the G20.

Queensland Police Assistant Commissioner Katarina Carroll says officers at the new G20 operations centre have already started watching the city around the clock.

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She says hundreds of surveillance cameras are watching Brisbane Airport, major roads, the CBD, South Bank and even hovering above in police helicopters.

Ms Carroll says the state-of-the-art operations centre is “the envy of all of our counterparts interstate”.

“It’s unprecedented as to what footage we will have available to us,” Ms Carroll told reporters on Sunday.

“So obviously it puts (us) in good stead to ensure that, for instance, the motorcades are very, very safe.”

Ms Carroll said the size of the world leaders’ motorcades was still being negotiated, but she said some were very long, which would be difficult to work with in the CBD.

“That’s still in negotiation, and certainly from our point of view if it was smaller it would be easier to work with, but obviously that discussion happens with prime minister and cabinet initially and then with the Queensland Police Service,” she said.

Dozens of police tactical commanders are based at the new operations centre, including those in charge of public order, special emergency response, motorcades, route security and bomb searches.

Ms Carroll said hundreds of local, interstate and New Zealand police have also briefed on procedures over the weekend.