Airports are alerting passengers to possible delays due to the current alert status.
The below information from Bristol is an example
With the recent incident in Manchester and the UK threat level increasing to ‘Critical’ we are advising passengers to allow extra time for their journey through the airport. This week we have experienced some queues in numerous areas of the airport which has impacted some passengers travel plans so please advise passengers to give themselves additional time for their journey through the airport.
We have communicated the below message out to passengers via social media and other forms of distribution to try and give them this information.
The safety and security of passengers and staff is our highest priority.
As a precautionary measure and in line with other key transport hub locations, passengers will see an increased number of police officers – both armed and unarmed – on duty in and around Bristol Airport providing a highly visible presence. These measures will remain in place as long as required.
Bristol Airport has recently invested in state-of-the-art screening technology which together with a dedicated security team will mean that passengers will both be safe and feel safe when travelling. All check-in, bag drop and security search processes will continue to operate at our consistently high standards.
We recommend passengers always allow plenty of time when arriving for a flight in case of any unexpected delays, leaving enough time to complete the normal check-in and security processes.
We remind all passengers to be extra vigilant whilst at the Airport, not to leave personal belongings unattended at any time, and to report any suspicious behaviour to the Police or Airport staff.