Downing Street has confirmed there will be a ban on electronic devices on flights to the UK from six countries in the Middle East and North Africa.
The policy, to be introduced in a couple of days, will ensure passengers from these countries will not be able to carry laptops and electronic devices "larger than a typical smartphone" as carry-on luggage.
These devices will have to go into the cargo hold for the duration of the flight.
Passengers from Lebanon, Saudi Arabia, Tunisia, Egypt, Turkey, and Jordan will be affected by the measure.
It is not clear if this move by Theresa May is in response to a specific terror threat.
Some of the airlines affected by this will be British Airways, easyJet, Royal Jordanian, and Turkish Airlines.
Transport Secretary Chris Grayling said: "We understand the frustration these measures may cause and we are working with the aviation industry to minimise impacts."