A major terrorist plot to blow up planes in mid-flight has been disrupted, Scotland Yard has said.
All airports have been put under the restrictions
It is thought the plan was to detonate explosive devices smuggled on aircraft in hand luggage, with flights from the UK to the US being targeted.
During the night, police arrested a number of people in London after a counter-terrorist operation they said had lasted several months.
Security at all airports in the UK has been tightened and delays are expected.
We will have more on the foiled attacks on Friday's Breakfast, and will be updating this page with more advice and information
INFORMATION AND ADVICE FOR AIR TRAVELLERS
Events are changing rapidly, so please bear with us while we check for the latest information and advice, but this is what we know so far:
Anyone travelling from a UK airport can expect severe delays possibly up to five hours - allow extra time but do still check-in at the time requested by your airline. By 0830 Thursday morning several airlines were starting to announce cancellations
Heathrow Airport: At 0845, London Heathrow announced that no more aircraft would be allowed to land at the airport due to congestion on the ground; staff there have also asked that anyone who does not need to travel to the airport to stay away.
The scene at Heathrow early Thursday morning
All hand luggage will have to be checked-in with your hold luggage, you will only be allowed a small, clear
plastic bags with essential items such as medication and a wallet or small purse
You will not be able to take a mobile phone or laptop computer on board and aircraft today, and it's not known how long the strict security will be in place for
BAA is responsible for London Heathrow, Gatwick, Stansted airports; and Glasgow, Edinburgh, Aberdeen and Southampton. You will be able to get more information from its website - at time of writing it is very hard to connect to because of the number of people trying to access it.
The Security Service - MI5, has raised the threat level in the UK to 'critical' - the highest
The Department for Transport has issued this guidance:
Revised travel arrangements, issued at 0700 on Thursday
With immediate effect, the following arrangements apply to all passengers starting their journey at a UK airport and to those transferring between flights at a UK airport
All cabin baggage must be processed as hold baggage and carried in the hold of passenger aircraft departing UK airports
Passengers may take through the airport security search point, in a single (ideally transparent) plastic carrier bag, only the following items - (nothing may be carried in pockets):
Pocket size wallets and pocket size purses plus contents, for example money, credit cards, identity cards etc but not handbags
Travel documents essential for the journey (for example passports and travel tickets)
Prescription medicines and medical items sufficient and essential for the flight (e.g., diabetic kit), except in liquid form unless verified as authentic
Spectacles and sunglasses, without cases, contact lens holders, without bottles of solution
For those travelling with an infant: baby food, milk (the contents of each bottle must be tasted by the accompanying passenger) and sanitary items sufficient and essential for the flight (nappies, wipes, creams and nappy disposal bags)
Female sanitary items sufficient and essential for the flight, if unboxed (e.g. tampons, pads, towels and wipes) and tissues (unboxed) and/or handkerchiefs
Keys (but no electrical key fobs)
All passengers must be hand searched, and their footwear and all the items they are carrying must be X-ray screened
Pushchairs and walking aids must be X-ray screened, and only airport-provided wheelchairs may pass through the screening point
In addition, all passengers boarding flights to the USA and all the items they are carrying, including those acquired after the central screening point, must be subjected to a secondary search at the boarding gate. Any liquids discovered (will) be taken from the passenger
There are no changes to current hold baggage security measures
Information from government websites
The Foreign Office, Home Office and Department for Transport will all be putting information on their websites expected to be updated throughout the day, but may be hard to access due to volume of people trying at once -
The Metropolitan Police has put a news briefing about the anti-terrorism operation to prevent aircraft from being blown up on its website.
At the time of writing, Heathrow airport had stopped accepting any inbound flights, this is due to congestion on the ground by delayed aircraft.
The airline is appealing for people who do not need to travel today to stay at home of they can, and if you do need to travel check its website
The Association of British Travel Agents - ABTA - has information on its website regarding the disruption for holidaymakers.
Scotland Yard said in a statement: "We would like to reassure the public that this operation was carried out with public safety uppermost in our minds.
"This is a major operation which inevitably will be lengthy and complex."
BBC journalist Joe Lynam encountered the increased security measures at Gatwick airport.
"I was handed a piece of paper saying that pretty much nothing could be taken on board the plane," he said.
"Everything had to be checked in and that includes mobile phones, ipods, wallets - even spectacle cases had to be checked in."
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