Operations at Brisbane's domestic airport are returning to normal after a security breach caused extensive delays this afternoon.

A Qantas spokeswoman says several passengers inadvertently walked through an exit door just after 5.00pm AEST, forcing the evacuation of a secure zone.

The security screening of passengers was delayed for more than an hour.

Arriving passengers were forced to wait on board their aircraft on the tarmac while airport authorities re-established security screening.

Departing flights were also delayed but officials say all flights out of the domestic terminal will go ahead tonight.

Re screening is now complete following the earlier security breech (sic). Operations at BNE Dom getting back to normal. Thanks for your patience.

Earlier, affected passengers took to Twitter to voice their frustrations.

Security breach at Brisbane Airport. Everyone had to exit and go trough security check again! Really delayed.

Landed 40 mins late and guess what.... Not letting us off flight. Security breach whole airport has been evacuated. Ack!