Top U.S. government and law enforcement officials are increasingly concerned that al-Qaida and other terrorist organizations may soon use computers to attack Americans inside the United States. They have said there is significant evidence al-Qaida could be planning to use cyber-terrorism to attack America's infrastructure with the goal of causing widespread financial damage and bloodshed.

Law enforcement and national security officials say computers seized in al-Qaida hideouts in Afghanistan contained a great deal of information about America's computer networks that control huge industries throughout the country. It was a discovery that commanded urgent attention at the White House.

The Director of the Federal Bureau of Investigation (FBI), Robert Mueller, told a recent national forum on combating cyber-terrorism that his agency is worried al-Qaida and other terrorist groups may use computers to launch a major attack on America's infrastructure.

"Our concern with al-Qaida fragmented and with al-Qaida with substantial levels of expertise in a number of its associated persons is that 10 or 15 can get together in various countries and orchestrate some sort of cyber attack. We have spent a substantial amount of time trying to understand al-Qaida's capabilities and the capabilities of other nation states and we spend a substantial amount of time and money in anticipating attacks on the infrastructure and trying to protect against such attacks," he said.

If al-Qaida and other terrorist organizations use the Internet for attacks, it will represent a new threat that does not resemble familiar computer disruptions caused by hackers responsible for viruses and worms that cause financial damage.

For example, if al-Qaida is successful taking computer command of large electrical power grids or the floodgates of a dam, it could use them as tools to destroy property and lives. "There is no doubt that the terrorists around the world and al-Qaida in particular see cyber-terrorism as part of one of their ways to attack that which they hate, which is civilization and strong economies," says Harris Miller, president of the Information Technology Association of America. The organization is a Washington-based trade group that represents most of the major information technology companies in the United States.

Mr. Miller expects terrorist groups to try to combine a large physical attack on U.S. infrastructure with an assault on computer systems that move information and technology. "The potential perfect storm so to speak would be some kind of terrorist attack which would combine a physical attack with a cyber disruption. For example, a physical attack on a major city that was accompanied by an attack on the telecommunications system using the cyber access to it. So you would have not only the terrible physical destruction that might accompany a physical attack but you would have a communications breakdown that would harm the ability of first responders to respond. Government would be paralyzed in terms of how to adequately respond. That would just make whatever physical attack that occurred that much worse," he said.

U.S. President George W. Bush created the U.S. Critical Infrastructure Protection Board soon after the September 11 terrorist attacks last year. He ordered members to come up with a strategy for securing cyberspace and protecting industries heavily dependent on networked computers such as manufacturing, utilities, banking and communications.

The vice chairman of the board, Howard Schmidt, says evidence al-Qaida is targeting such infrastructure makes it important for the government and private industry to act quickly. "Well, it is obviously very, very disconcerting because the fact that we know they have the desire, we know they have the intent, and we just want to make sure we do not give them any opportunity. So we have taken everything that we have heard from all sources on that and once again use that to reinforce our ability to secure some of those systems that they evidently have interest in," Mr. Schmidt said.

Last September the White House issued a lengthy draft of a plan called the National Strategy to Secure Cyberspace.

Officials who wrote the plan say they hope it will serve as a clear road map to protect America's infrastructure.

The White House is seeking input from the private sector since the majority of America's cyber resources are controlled by entities outside the government.

A final report is due out in the next several months.