Nineteen people held on suspicion of plotting to blow up planes have had their UK assets frozen.
The police raided several houses across England
The Bank of England named the 19 and said it would be an offence to make their money available without a licence from the Treasury.
The UK remains on a "critical" level of alert as police investigate an alleged plot to attack UK to US flights.
Twenty-four people are being questioned by anti-terrorism police who said the plot could have led to "mass murder".
Following the arrests, Home Secretary John Reid said the police were confident that the "main players" had been accounted for.
But US government sources claimed that British officials were aware of five suspects who remained at large.
It is thought that the suspects were planning to blow up several planes by using liquid explosives carried in soft-drink bottles, and detonators disguised as electronic equipment.
UK police said the explosions could have caused "mass murder on an unimaginable scale".
Officials in Pakistan said security forces in the country had arrested two British men of Pakistani origin in connection with the alleged plot.
They were picked up from Lahore and Karachi cities last week.
On Thursday, Pakistan announced it had made a number of arrests in connection with the investigation.
US Homeland Security Secretary Michael Chertoff said the plot was "in some respects suggestive of al-Qaeda".
The suspects were rounded up in raids in London, High Wycombe in Buckinghamshire, and the West Midlands. All are being held in London.
Searches continued at several addresses and people were evacuated from some homes in High Wycombe.
Following the police operation, airports throughout the UK issued strict new security measures.
Armed police have been deployed in many airports and passengers are no longer allowed to take their hand luggage into the cabin.
Many flights on Thursday were grounded and further delays are expected on Friday.
Ed Balls, economic secretary to the Treasury, said in a statement that the decision to take financial action was taken on the advice of the police and security services.
"The Treasury has instructed the Bank of England to issue notices to effect a freeze of the assets of a number of individuals arrested in yesterday's operations," he said.
This was done under the terms of the Terrorism (United Nations Measures) Order 2001, he said.
"The Treasury will review the need for further use of our asset-freezing powers as we receive further advice from the police and security services."
Call for vigilance
Meanwhile Home Secretary John Reid has urged people of all communities and religions in the UK to join together to overcome "those who wish to harm us".
He said people should remain vigilant but "carry on as normal" amid the continuing security alert.
This was vital to prevent "evil people", who seek to destroy the UK's values and spirit, from winning, he added.
Mr Reid praised the fortitude and patience of passengers affected by the increased security at airports across the UK.