The UK security threat level is to stay at "critical" following a suspected plot to blow up passenger planes, Home Secretary John Reid has said.
He said he believed the main suspects were in custody but it was right to "err on the side of caution".
Everyone faced the threat and everyone "should respond with a common purpose and common solidarity", Mr Reid added.
Nineteen of 24 people arrested have had their UK assets frozen. The names have been published by the Bank of England.
Meanwhile, Deputy Prime Minister John Prescott has paid tribute to the way the UK has reacted to an "extraordinary" past 36 hours "in the efforts to protect this country".
He expressed his "deepest appreciation" to the "real dedication" shown by security services, police, transport staff and aviation companies and praised Mr Reid and Transport Secretary Douglas Alexander.
The British public had also acted "calmly, sensitively and with great patience", he added.
It is thought that the group of 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, who were picked up in Lahore and Karachi last week.
The Pakistan Foreign Ministry has identified one of the men as Rashid Rauf. "There are indications of Afghanistan-based Al-Qaeda connection," a spokesman said.
Pakistan has previously said it had made a number of arrests in connection with the investigation.
The Home Office has refused to confirm reports that Thursday's anti-terror operation in the UK was triggered by the interception of a decoded message sent by a suspect in Pakistan, which gave the go-ahead for the attack to take place.
At a news conference, Mr Reid said he was "grateful" for the help of the international community, in particular Pakistan, in disrupting the suspected plot.
Armed police have been out in many UK airports
The home secretary also made a plea for all communities to work together to face the danger.
"More than ever we need to draw on the tolerance and resilience of all parts of our community in the days ahead," he said.
"This is a common threat to all of us and we should respond - all of us - with a common purpose and common solidarity.
"This is in the nature of the British people and that common solidarity and common cause is, I believe, now our most precious asset and we should foster it in all sections of our community."
Later on Friday afternoon, Mr Reid chaired a meeting of Cobra - the government's emergencies committee.
Mr Alexander, who was at the meeting, reiterated that the security threat level would stay at its highest level while the investigation continued.
And hand-baggage restrictions would also remain in place for the foreseeable future, he told BBC News.
"I don't think we will be able to return to what we had in the past," he added.
Flights from UK airports are still being delayed as passengers go through strict security checks.
Services are returning to normal, but travellers are being warned to check with airlines before they set off.
Meanwhile, the FBI in America say they are following "new leads" in their investigation into the suspected plot, according to the BBC's North America business correspondent Guto Harri.
They were working on "a fresh new wave" of material provided by UK police and secret services, he added.
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.
Thames Valley Police say they seized computer equipment during a search at an internet cafe in Reading on Thursday, but that no arrests were made.
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.
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 and done under the terms of the Terrorism (United Nations Measures) Order 2001.
NEW THREAT LEVELS
Low - an attack is unlikely
Moderate - an attack is possible but not likely
Substantial - strong possibility of an attack
Severe - an attack is highly likely
Critical - an attack is expected imminently