FBI agents were yesterday searching for a white American man in connection with Saturday morning's bomb attack in Atlanta in which two people died and 110 were injured.

There were more bomb alerts across Atlanta yesterday, including at the Olympic Athletes' Village, which caused new problems for the authorities.

The FBI said it was making good progress and had "promising leads" in its investigation into the attack in the Centennial Olympic Park.

In the early hours of Saturday morning, a crude pipe bomb sent packed nails and screws scything through the crowd during a rock concert in the packed entertainment park.

President Clinton said yesterday he had invited leaders of the US Congress to the White House today to discuss expanding wiretapping and chemically tagging explosives to help suppress terrorism.

A police spokesman said yesterday the Atlanta investigation was focused on a white man who made an emergency call to police warning of the bomb 13 minutes before it exploded.

There was stringent security yesterday to enable the Games to continue, with police and army bomb disposal experts answering more than loo calls reporting suspicious packages throughout the city.

US television showed footage of passengers being evacuated from Five Points, a key city centre station subway. The station is just a few hundred yards from the park.

The US, once immune at home from terrorisms' worst excesses, was in shock this weekend. The blast occurred 10 days after 230 people died in the still unexplained crash of a TWA jet.

An extreme right wing Georgia militia group yesterday denied it was behind the Atlanta attack and condemned it as cowardly.

A spokeswoman for a group called the "112th Regiment Militia at Large for the Republic of Georgia" told a news conference. "It's so absurd when they say we re doing something like this. This is the last thing we want."

The 10,000 athletes at the world's greatest sporting event tried to block out the tragedy and get on with competing. Organisers promised the Atlanta games would still succeed.

I don't believe Atlanta will be remembered for this terrorist act but for the fact that we overcame this tragedy and moved forward and put on a magnificent spectacle for athletes," said the Mayor of Atlanta, Mr Bill Campbell.

He said swift work by security forces had saved "literally hundreds" of lives in the blast at the entertainment area.

Big crowds again turned out for Games yesterday but there were also packed churches for services to mourn the two dead victims and sympathise with the injured. A 44 year old woman from Albany, Georgia, was killed by the bomb and a Turkish cameraman died from a heart attack.

President Jacques Chirac of France and the Israeli Prime Minister, Mr Benjamin Netanyahu, both telephoned President Clinton yesterday to express their dismay. President Clinton, on the eve of a Group of Seven (G7) summit in Paris which is to address the question of how democratic states should respond to the growth of international terrorism, denounced the attack as an "evil act of terror". The family of Ms Alice Hawthorne, the American woman who died, has complained that neither ACOG nor the International Olympic Committee had contacted them.

An organising committee spokesman said later the park, designed to be the life and soul of the Games, would open today with doubled security, increased surveillance and random bag searches.

The warning call to police came from a public telephone outside a hotel adjoining the park. The phone had been taken away for forensic tests at FBI laboratories in Washington.

Voice experts identified the caller as a white American. Last might the FBI was preparing sketches of possible suspects.

The Atlanta police chief, Ms Beverly Harvard, rejected suggestions that police should have cleared the packed park quicker after receiving the warning call. He said they were continuing to review their routines.

"We have a protocol used to react to bomb calls. We have received dozens of bomb calls...We are looking at the protocol," she said.

A British terrorism expert, Mr David Capitanchik, claimed yesterday the perpetrators were beginning to look like a domestic group opposed to the re election in November of President Clinton.

Israeli experts echoed this view, saying the amateurishness of the bombing suggested it was more likely the work of an angry or frustrated American than international guerrillas.

The International Olympic Committee president, Mr Juan Antonio Samaranch, said he was impressed by the work of the security forces after the blast.

"We are very grateful to the authorities for their excellent response and for the security measures they have taken," a sombre Mr Samaranch told a news conference.

Thousands of Olympic spectators were forced to take enormous detours in the rain yesterday around the park. Ticket holders, the media and athletes were subjected to searches at security points before entering the venues. Most accepted the delays with good humour.