Angry passengers were forced to discard expensive perfumes, toiletries and alcohol at check-in Brussels on Tuesday morning without any prior warning.
Security checks were also tightened and extra officers deployed after Belgian federal police received a warning of a potential threat to the 10.56am Brussels to London service.
Eurostar normally places no limit on the amount of liquids which can be carried on the service, with the international rail service’s official website telling passengers they can “even squeeze in a bottle of bubbly”
In contrast, passengers were banned from carrying more than 100ml of liquids in their hand luggage on flights in 2006, when the Government uncovered a terror plot to blow up transatlantic jets using “liquid bombs”.
There have been a series of measures to tighten airline security since the 9/11 attacks on the United States in 2001.
Writing on Twitter about the Eurostar ban, one passenger named Ursula said: “Send an email or at least tweet on the liquids next time. I had to throw away my perfume – was my Xmas present.”
On Facebook, another passenger said: “Warning! I just took the Eurostar in Brussels and ALL liquids are now forbidden. No perfume, no shampoo, no beer… terrible to throw them all away.”
A spokesman said Eurostar’s security measures procedures were set up by the authorities in each country the service stops in, and any changes are due to advice from the relevant authority.
He added: “Our services always operate at the highest levels of security, with 100 per cent of bags and passengers checked before departure.
“Security procedures are set by the authorities, and on some occasions we may be advised to implement additional checks. This was the case with one Brussels service this week.”
Security measures are being tightened on travel services around the world, and just last week, the UK implemented a ban on laptops and other large electronic devices in airline cabin baggage from Turkey, Lebanon, Egypt, Saudi Arabia, Jordan and Tunisia.
A Government spokesperson said: “The safety and security of the travelling public is our highest priority. That is why we keep our aviation security under constant review and put in place measures we believe are necessary, effective and proportionate.
“The Prime Minister has chaired a number of meetings on aviation security over the last few weeks, including this morning, where it was agreed that new aviation security measures on all inbound direct flights to the UK from the following countries will be introduced: Turkey, Lebanon, Jordan, Egypt, Tunisia, Saudi Arabia.
“We have been in close touch with the Americans to fully understand their position. Airlines affected are being informed of the new requirements.
“Under the new arrangements, passengers boarding flights to the UK from the countries affected will not be allowed to take any phones, laptops or tablets larger than a normal sized mobile or smart phone (larger than Length: 16.0cm, Width: 9.3cm, Depth: 1.5cm) into the cabin of the plane. Any such devices will need to be placed into hold luggage and checked-in before going through central security. Normal cabin baggage restrictions will continue to apply.
“The additional security measures may cause some disruption for passengers and flights, and we understand the frustration that will cause, but our top priority will always be to maintain the safety of British nationals.”
