Cairns Airport's domestic terminal has been evacuated and all passengers screened again after a security breach in which a woman briefly entered a restricted area.
Passengers took to social media to share their frustration at being delayed on the tarmac and forced to go through security again.
Cairns Airport issued a statement through social media at 2pm saying the domestic terminal had been evacuated "due to a suspected security breach".
"All passengers are currently being re-screened and we anticipate operations will return back to normal very soon," the statement said.
"We appreciate your patience and understanding during this time."
The Australian Federal Police confirmed they were on-site during the lockdown.
"At no stage was there a threat to public safety," a spokesperson said.
"Inquiries into this matter remain ongoing and no charges have been laid at this stage."
One passenger told Fairfax Media that passengers had been told there was a security breach in the international terminal, grounding all planes.
Operations returned to normal just before 3pm with passengers allowed back through security and planes permitted to land and depart.