British airports and nuclear power plants have been ordered to tighten security over fears terrorist hackers could have found a way to bypass electronic safety checks.

Over the last 24 hours, spies have given a series of warnings terrorists might have discovered means of bypassing scanners in airports and security at nuclear facilities.

There are fears Islamic State terrorists could put bombs in mobile phones and laptops that would not be picked up by screening, The Sunday Telegraph reported.

This is believed to be the reason behind the USA and Britain's ban on travellers carrying laptops and large electronic devices from six countries. 

Security officials are also concerned terrorists, spies or 'hacktivists' are looking for ways to take advantage of 'vulnerabilities' at nuclear power stations

The ban on laptops on British-bound travellers covers all direct flights from Turkey, Lebanon, Jordan, Egypt, Tunisia, and Saudi Arabia.