The UK ban applies to 6 countries, while the US ban applies to eight Muslim-majority countries.

Britain joined the United States on Tuesday in banning passengers traveling from airports in several Muslim-majority countries from bringing laptops, tablets and other portable electronic devices on board with them when they fly.The U.K. ban applies to six countries, while the U.S. ban applies to 10 airports in eight Muslim-majority countries.Fliers can still travel with these items, but they must be packed in their checked baggage on U.S.- and U.K-bound flights from airports across the countries including busy transit hubs in Istanbul, Dubai and Doha, Qatar.The British ban will also include some cellphones and is expected to apply to all aiports in the six nations.A spokesman for the British Prime Minister's office said the mesaures were based on the "same intelligence the U.S. relies on."Senior U.S. administration officials said the rules were prompted by "evaluated intelligence" that terrorists continue to target commercial aviation by "smuggling explosives in portable electronic devices.""Based on this information, Secretary of Homeland Security John Kelly and Transportation Security Administration acting administrator Huban Gowadia have determined it is necessary to enhance security procedures for passengers at certain last-point-of-departure airports to the United States," officials said late Monday.Federal officials initially described the ban as indefinite. But a spokesman for the Department of Homeland Security, David Lapan, said the directive runs until Oct. 14 and could be extended for another year "should the evaluation of the threat remain the same."The officials would not provide details on the threats. One example they cited involved a bomb, possibly hidden in a laptop, that exploded on board a Somali plane going from Mogadishu to Djibouti, not a U.S.-bound flight.However, a person familiar with the security warning said the government has long been concerned about the aspirations of a Syria-based terrorist group to build explosive devices hidden inside electronics in a way that would be hard to detect.In 2014, such concerns led to a tightening of security procedures on U.S.-bound flights, but at the time, some officials said the design of such devices did not appear to have moved past the planning stages. One person familiar with the new restrictions said they were based on more recent intelligence that suggested terrorists had gotten further along in developing such hidden explosives.Under the restrictions, travelers to the United States from 10 mostly Middle Eastern airports will be required to put all personal electronic devices larger than a cellphone or smartphone in their checked baggage. U.S. airlines are not affected by the ban because none offer direct U.S.-bound flights from the affected airports.Ten airports in eight countries - Egypt, Jordan, Kuwait, Morocco, Qatar, Turkey, Saudi Arabia and the United Arab Emirates - are affected. Officials said the airports were selected based on the "current threat picture."The airports are: Queen Alia International Airport (AMM) in Jordan, Cairo International Airport (CAI) in Egypt, Ataturk International Airport (IST) in Turkey, King Abdulaziz International Airport (JED) and King Khalid International Airport (RUH) in Saudi Arabia, Kuwait International Airport (KWI) in Kuwait, Mohammed V International Airport (CMN) in Morocco, Hamad International Airport (DOH) in Qatar and Dubai International Airport (DXB) and Abu Dhabi International Airport (AUH) in the United Arab Emirates.Officials said the change will affect passengers who travel on roughly 50 daily flights. Crew members are not included in the device ban.Turkey's transport minister, Ahmet Arslan, criticized the banTuesday, telling reporters in Ankara that it was not "beneficial" for passengers and that Turkey already has stringent security measures in place, according to Turkey's semi-official Anadolu news agency. He added that Turkish officials had spoken about the regulations with their American counterparts and were discussing whether the Trump administration should "step back."Word of the ban was first made public Monday afternoon - not by administration officials, but in a tweet sent out by Royal Jordanian Airlines. Initially, U.S. officials declined to comment on the report, saying only that they would provide an update "when appropriate."In the tweet, which was later deleted, airline officials advised passengers of the new requirements that would affect travelers on its flights to New York, Chicago, and Detroit and Montreal."Following instructions from certain concerned US departments, we kindly inform our dearest passengers departing to and arriving from the United States that carrying any electronic or electrical device on board the flight cabins is strictly prohibited," the tweet read.It noted that cellphones and medical devices are excluded from the ban.Emirates Airlines issued a similar statement Tuesday, saying "electronic devices larger than a cell phone/smart phone, excluding medical devices, cannot be carried in the cabin of the aircraft" on U.S.-bound flights. The U.S. routes of Emirates include Dulles International Airport.Late Monday evening, the airline issued a follow-up tweet: "Further updates will be announced soon regarding #electronicban."U.S. officials began outlining the new rules to carriers Sunday.A spokesman for the International Air Transport Association, which represents international carriers including Royal Jordanian, said they were not informed of the new restrictions and were working to get additional information from U.S. authorities.

Officials said airlines will have 96 hours to comply with the restrictions. Carriers that fail to follow them risk losing their authorization to operate in the United States.