A major terrorist plot to blow up planes in mid-flight has been disrupted by police, Scotland Yard says.
It is thought the plan was to detonate explosive devices smuggled on board aircraft in hand luggage.
During the night, police arrested a number of people in London after a counter-terrorist operation they said had lasted several months.
Police believe the attacks would have been particularly targeted at flights from the UK to the US.
The Department for Transport said security at all UK airports has been increased.
Passengers on all flights will not be allowed to take any hand luggage on to any flights in the UK.
Only the barest essentials - including passports and wallets - will be allowed to be carried on board in transparent plastic bags.
Just saw it on the BBC Breakfast news.
I guess we can expect a whole lot of delays today and in the coming days.