The UK Department for Transport will install security scanners in 11 more airports, in a move to detect threats posed by non-metallic improvised explosive devices (IEDs).
The security scanners are already in place in ten airports in the country, and are set to be added in Stansted, Luton, Bristol, Liverpool, Newcastle, Aberdeen, Leeds Bradford, East Midlands, Prestwick, Cardiff and Belfast City airports.
UK Transport Secretary Patrick McLoughlin said that the latest scanners do not pose health risks and the automatic threat recognition software does not require an image of a passenger.
McLoughlin said that passengers who opt out of being screened by a security scanner will be allowed a private search alternative.
The alternative arrangements will be analysed in order to ensure that high levels of security are maintained.
Passengers who oppose security scanners will not be allowed to fly if they refuse to undergo an alternative security scan.
"Where it can be demonstrated that another security process, or combination of processes, offer the same level of security as a scan, then I will consider allowing further alternatives to a private search to be offered to passengers," McLoughlin said.
The scanners were installed in response to threat perceived from non-metallic IEDs, which are difficult to be scanned with the conventional screening.
Non-metallic IEDs are the ones used in the attack on Northwest Flight 253 from Amsterdam Schiphol to Detroit in 2009, and the device recovered in Yemen in 2012.
Meanwhile, the minister said that it is being contemplated to increase the number of scanners in the ten airports that already have a few in place.