Two new youth detention centres would be built in Queensland under an LNP government, as the Opposition Leader again pushes his party's law and order credentials.

Tim Nicholls delivered the pledge while visiting Cairns this morning.

The "medium security" centres would hold 17 to 25-year-olds at a cost of $40 million.

One would be built in the far north, the other in the south-east.

"It'll be in the Cairns region, it may be co-located with an existing facility or it may be a new stand-alone facility, and we'll see it both in the south-east and here in Cairns," Mr Nicholls said.

He said the two new facilities would be in addition to the Cleveland Youth Detention Centre in Townsville and the Brisbane Youth Detention Centre, adding a further 90 beds.

Mr Nicholls announces the Reintegration Centre policy in Cairns. ( ABC News: Josh Bavas )

"We will work with the department on the best location for what we're calling 'reintegration centres'. These are centres that we'll be using to train young people to give them the skills they need to get back into society," he said.

Mr Nicholls said he would also do away with suburban bail houses.

"Labor's plan for community bail houses is a knee-jerk reaction, it hasn't thought through the program properly — this is actually a comprehensive program," he said.

"The LNP's made commitments to make our communities safe and liveable, to make sure the young thugs don't just come into your house, knock off your car, scream off down the street and leave you in their wake having to pick up the pieces."

He said an LNP government would also work to retrain youth detention staff.

The party's also pledged an extra $3 million towards youth advocacy centres, and $1.5 million to help reduce homelessness.

Cost doesn't add up, Palaszczuk says

Premier Annastacia Palaszczuk said Mr Nicholls may have underestimated the cost.

"The cost of building a correctional facility or a youth detention centre would be probably in the vicinity of like $100 million for each one," she said.

Ms Palaszczuk (R) says bail houses are for youths who have nowhere to go. ( ABC News: Chris O'Brien )

She also defended Labor's bail houses policy.

"The bail houses are for youths that are currently on bail and have nowhere to go," she said.

"They can not go home to their families because there may be domestic violence issues, there may be issues around drugs and alcohol.

"This is making sure they're supervised."