President Bush said yesterday the United States has locked up $6 million in bank accounts tied to terrorists amid reports of a widening search for the financial underpinnings of Osama bin Laden's al-Qaeda network.

`Thus far we have frozen about $6 million in banking accounts linked to terrorist activity,'' Bush said yesterday. ``We have frozen 30 al-Qaeda accounts in the U.S. and 20 overseas. And we are just beginning.''

But the action Bush described caused some to wonder why it took the devastating attacks of Sept. 11 to spur the government to target those accounts.

``Somebody was asleep at the switch there,'' said Michael Kessler, a forensic accounting specialist in New York who was a consultant in the investigation of the 1993 World Trade Center bombing there. ``They could have been subpoenaing bank accounts and looking at transactions (of suspected bin Laden associates) long ago.'' 

Kessler said there was ``definitely an intelligence gap,'' but that it is time to move past hindsight to ensure no other terrorist-linked accounts remain active. 

One of the keys to laying bare the roots of terrorist funding will be to overcome the clandestine nature of financial transactions around the world, experts said. 

``My advice would be simply to follow the trail and to break the rules of secrecy,'' said Tamar Frankel, a Boston University law professor and finance expert. 

As investigators peel back the layers of contributors to particular charities and other organizations believed to provide funding to terrorist groups, they will keep finding additional levels and groups to look into, Frankel said. 

``I expect the numbers to keep growing,'' she said. 

The Bush administration is preparing to freeze the assets of two dozen more charities and other organizations, The New York Times reported yesterday, citing unnamed government sources. Last week, the administration froze the assets of 27 groups and individuals, including three charities. 

The officials reportedly said they have discovered financial networks for terrorists extending from the United Arab Emirates to Europe and Indonesia. 

Among charitable groups said to be under investigation are the Benevolence International Foundation and the Global Relief Foundation, both of which have offices in Illinois. 

Benevolence International, in a prepared statement, said recent reports linking it to the Sept. 11 attack were ``false rumors and innuendoes.'' Global Relief did not respond to a call for comment. 

International efforts targeting terrorist funds produced results yesterday. 

British officials yesterday said they froze $88.4 million in bank funds tied to bin Laden or al-Qaeda. The investigation that led to the action began in 1999 following a United Nations resolution on terrorism, British officials said. 

And Swiss banking giant UBS AG yesterday said it alerted authorities to suspicions about ``four small payment flows, three in the Americas and one in Europe.'' 

What will help the investigation the most in the end, Frankel said, is that most of the channels of moving money, whether through charities or banks, are fairly well regulated and leave some sort of paper or electronic trail. 

Some experts caution that terrorist groups may pay operatives with cash or with the gains from petty crimes like credit card fraud. 

``Everybody seems to think they'll be able to trace this all back to its source, but that's not necessarily true,'' said D. Larry Crumbly, a Louisiana State University accounting professor and editor of the Journal of Forensic Accounting. 

``There are reports they used a lot of cash. Once you start using cash, the trail stops,'' he said. 

Frankel, however, said moving cash is more difficult than many people seem to realize. 

``Very little money can really be transferred in brown bags, especially internationally. You need some channel, whether a bank or a mutual fund or some other organization - and they are easier to trace,'' she said.