Bins have been welded shut at Brisbane's busiest train stations in a response to the raising of the national terrorism threat level.

The trash receptacles at stations between Bowen Hills and South Brisbane, and at Toowong were welded over the weekend and will remain closed until further notice.

The stations have been identified as some of the busiest in Brisbane, and have been decorated with laminated signs explaining the situation.

Laminated signs have been placed on bins around Brisbane's busiest train stations

Bins have been welded shut in response to the nationally raised terrorist threat level

Commuters are now unable to use the bins which will be removed altogether later this week

The signs say,

'For safety reasons this bin is no longer available,'

'Please take your rubbish with you,'

'We apologise for any inconvenience.'

Extra police have been installed at the city stations in a further response to the terrorism threat level.

A spokesperson for Queensland Rail said that the bins would be removed completely in the near future, reported The Daily Telegraph.

'Those particular bins will be removed indefinitely,' she said.

'It’s stations where there’ll be large crowds... basically our busiest stations.'

Queensland Rail was reported to have an established security plan which is linked to the Federal Government’s National Terrorism Public Alerts levels and has prompted the initiative.

Commuters were met by welded bins and extra police officers patrolling the train stations on Monday

The signs read, 'For safety reasons this bin is no longer available', 'Please take your rubbish with you'

'Because we are well prepared and practiced we were able to implement this plan as soon as the Federal Government raised the alert level,' the spokeswoman said.

On Friday night, public tours were cancelled at Parliament House, and extra security officers were assigned to the building.

Premier Campbell Newman declined to say when he would like the doors to be reopened to the public.