The FBI advised officials in as many as eight cities last month to tighten security in schools after U.S. soldiers raiding an apartment in Iraq seized computer disks containing information about those towns' school systems that was taken from Web sites, government officials said yesterday.

U.S. officials said they remain uncertain whether the Iraqi whose computer disks contained the school information was involved in terrorist activity, and stressed that the government has no evidence of a plot to attack any schools in this country.

Officials said they decided to issue the warnings to the school systems in New Jersey, Florida, Georgia, California and Oregon after the siege at a school in Beslan, Russia, by Chechen guerrillas last month ended with 338 deaths, half of them children. The computer disks had been discovered in Iraq several weeks before that, officials said.

In reviewing the information seized in Iraq, "officials didn't discover any direct threat, and the reason for collecting the school information is unknown," said Brian Roehrkasse, spokesman for the Department of Homeland Security.

The warnings were issued to officials in San Diego; Fort Myers, Fla.; Salem, Ore.; Gray, Ga.; Birch Run, Mich.; Rumson, N.J.; and a few other towns, officials said.

Intelligence officials theorize that the Iraqi man who owned the computer was a Baathist official now working as a civic planner, according to a government representative. The Department of Homeland Security's intelligence division decided the appearance of the school information on the disk was not an indication of a threat, but the FBI decided to notify the school districts after the Beslan massacre, he said.

Officials with the San Diego schools were notified last month by the FBI that a disk containing a public U.S. Department of Education report on crisis planning was found in the possession of a man arrested in Iraq by U.S authorities. The report mentions San Diego city schools but does not include the emergency crisis plan of the school district or any individual school, district spokeswoman Peri Lynn Turnbull said.

While San Diego district officials said there were no specific threats against any of their 202 campuses, some parents were keeping their children home yesterday after increased local and national media attention regarding the disk.

"The unfortunate thing is that parents are very concerned," Turnbull said. "We want them to know that it is safe for them to send their children to school."

Mary Paulson, a spokeswoman for the school district in Salem, Ore., quoted FBI agents there as saying that Web pages showing the floor plans of some schools in other states had been discovered on the computer disk.

Earlier this week, the U.S. Department of Education sent out an FBI-Homeland Security bulletin to all school districts in the country urging that they review their security procedures in light of the Beslan killings.

For nearly two years, the Education and Homeland Security departments have offered security tips to school officials on strengthening security on their campuses. But yesterday an expert on school security, Kenneth S. Trump, said U.S. officials have failed to publicly stress the need for better school protection.

"This week I guess they're coming out of their posture of 'downplay and deny' that they've had for years," said Trump, who is based in Ohio. He said he has long recommended that schools hold more sophisticated drills in tandem with the police to prepare for emergencies and that school systems stop posting school floor plans on the Web.