Disturbing reason why liquids were banned and then restricted to 100ml on flights

Frequent flyers will know all about the 100ml liquid rule with cabin luggage, and it can be a little - if not, very - frustrating for those traveling.

However, if you knew the real reason as to why the rule was introduced, then I think complaints would certainly be a lot quieter.

Back in 2006, British authorities were monitoring a London man named Abdulla Ahmed Ali after he was linked to an individual who tried to blow himself with a suicide vest on the capital's Underground the year before.

Liquids were banned in hand luggage because of the plot (Getty Stock Photo)

Ali was said to be in contact with other suspicious individuals with al-Qaeda ties based in both Britain and Pakistan.

UK officials informed the US of the man, which allowed Washington to monitor the emails and London to focus on the terrorist plotters.

As their investigate work continued, officials quickly came to the realization that the men, including Ali, were planning on bombing several commercial aircrafts bound for the US.

The plot has since been known as the '2006 transatlantic aircraft plot', as the group tried to denote liquid explosives disguised as soft drinks on flights from the UK to both the US and Canada.

Rashid Rauf, from Birmingham in the UK, is believed to have put the plotters in contact with al-Qaeda's leadership.

Rashid Rauf, a Briton allegedly involved with the plot (FAROOQ NAEEM/AFP via Getty Images)

Ali was surveilled by police upon his return to the UK from Pakistan in June 2006, with officials immediately having their suspicions of him.

After opening his hand luggage, they found a powered soft drink and a large number of batteries - a find that ultimately started the UK's largest surveillance operation to date.

The Met ended up calling an additional 220 officers from other forces to help with their investigation - and their search focused on a number of key individuals.

Assad Sarwar, from High Wycombe, raised suspicions as he purchased items that didn't seem required for his daily needs, with one instance seeing officers watch him dispose of empty hydrogen peroxide bottles at a recycling centre.

Both Sarwar and Ali were seen meeting in an east London park, which confirmed to officials the pair were working in unison.

The liquid rule on planes is all to do with our safety and security (Getty Stock Image)

MI5 managed to enter a flat being used by Ali, where they found a 'bomb factory'. They were able to install hidden cameras, which provided footage of Ali and Tanvir Hussain constructing devices out of drink bottles.

Come August 2006, police in the UK arrested 24 people for questioning, with eight of the suspects later charged with conspiracy to murder and commit acts of terrorism.

The was ultimately the reason why liquids were banned on flights and later limited to 100ml.