British casualties in the US terror attacks could be as high as 300, according to the Prime Minister.

Tony Blair has predicted grimly that the British death toll could rise to 200-300, making the suicide hijackings the worst terrorist outrage committed against the nation.

He made his comments during an interview in which he said Britain was "at war with terrorists" and in which he pledged full support for President George W Bush in America.

He said: "What happened was an attack not just on the United States, but an attack on the civilised world."

"It was the worst terror attack on British citizens since the Second World War."

Meanwhile the Government will pay for relatives of victims of the terror attack on the World Trade Centre to visit New York, Foreign Secretary Jack Straw has announced.

Two close relatives of Britons lost or missing in the atrocity are being offered flights, travel insurance and three nights' accommodation in New York.

Mr Straw said the Foreign Office was working hard to arrange the flights as quickly as possible.

Police family liaison officers are already in contact with the families and arrangements should be in place within the next few days, the FO said.

Mr Straw said: "Because of our close contact with the families, we know, and understand how keen many of the families are to get to New York.

"We are moving as fast as we can to make this happen," he said.

Culture Secretary Tessa Jowell, who is responsible for Government liaison with affected families, said: "These families have suffered the most terrible loss, and we have a responsibility to do all we can to help them."

The FO stressed that families who travelled to New York were not likely to be allowed close to the WTC site as safety restrictions were still in place.

A team of 30 consular staff, 20 British police office and 10 counsellors will be available to support the families in New York.

More than 20,000 Britons have already contacted helplines desperate to trace missing friends and relatives in America, Ms Jowell said.

The FO has a helpline for friends and relatives who have not yet been in contact: 0207 008 0000.

Related links Federal Emergency Management Agency White House Pentagon Emergency site Counter Terrorism Resource Centre Who is Osama bin Laden? FBI UK Government information and response

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