Today, we are taking another step in our fight against evil

President Bush

The move came as UK Prime Minister Tony Blair arrived in Washington for talks with President Bush.

Among those targeted are two financial networks, al-Taqwa, and al-Barakaat, which have outlets in several countries - the latter with several offices in the US.

Washington is also asking the authorities in several other countries to freeze the assets of people and groups suspected of links to Bin Laden.

Meanwhile, Italian news agencies reported that the government had frozen bank accounts linked to seven people on Washington's list.

Long list

In the wake of the 11 September attacks, the Bush administration had already moved to freeze the assets of 66 individuals, organisations and businesses.

Financial offices in four states were closed

The latest list includes names in the US, as well as Switzerland, Somalia, Liechtenstein, the Bahamas, Sweden and Canada.

Treasury Secretary Paul O'Neill said the US had blocked $24 million worth of Taleban and al-Qaeda funds, with at least another $43 million in assets being frozen in other countries around the world.

He said 112 countries have orders in force freezing the assets of organizations suspected of being linked to Bin Laden.

Nearly 1,000 more "suspect" accounts are under review, he said.

Mr Bush said that al-Taqwa and al-Barakaat "raise funds for al-Qaeda, manage, invest and distribute those funds, provide internet services and secure telephone connections, and arrange for the shipment of weapons".

"Today, we are taking another step in our fight against evil," he said.

Equal importance

White House spokesman Ari Fleischer said the "war on the financial front" was just as important as the US military action against al-Qaeda and the Taleban in Afghanistan.

Bush: Targeting funds

"The less money they have, the fewer missions they'll be able to carry out," he said.

Among offices targeted in the US, police sealed off a money-transfer business in Columbus, Ohio called Barakaat Enterprise, AP reported.

US officials have been stepping up investigations into informal, largely unregulated financial networks, known as hawalas, which are common in the Middle East, Reuters news agency said.

Movements of cash through such networks are extremely hard to trace because they work on trust and often do not involve the physical transfer of funds.

BBC business reporter Mark Gregory says a phone call or a coded message from one country is sufficient to release money held in another.