(CNN) -- More than 9,000 hate crime offenses -- more than half of them motivated by racial bias -- were reported last year, the FBI announced Monday.
The agency compiled reports of 7,783 criminal incidents involving 9,168 offenses "as a result of bias toward a particular race, religion, sexual orientation, ethnicity/national origin or disability."
Last year's figures cannot be compared with those of other years because the report relies on data submitted voluntarily by local law enforcement agencies, and "the level of participation varies from year to year," FBI spokesman Bill Carter told CNN.
"To be able to make comparisons from year to year is very difficult."
Published by the agency's Uniform Crime Reporting Program, "Hate Crimes Statistics, 2008" reports data about hate crimes submitted by law enforcement agencies nationwide.
The report breaks the hate crime offenses into two categories: crimes against people and crimes against property.
There were 5,542 crimes against people reported in 2008, it says. The most common was intimidation, which accounted for 48.8 percent of crimes against people. Simple assaults constituted 32.1 percent.
Of crimes against people, 31.9 percent took place "in or near residences or homes," according to the report. Another 17.4 percent took place on highways or other streets, roads or alleys.
Of the 3,608 crimes against property reported, 82.3 percent were acts of destruction, damage or vandalism, the agency said. The remaining 17.7 percent consisted of robbery, burglary, theft, arson and other offenses.
There were nearly 6,300 known offenders, according to the data. More than half -- 61.1 percent -- were white, while 20.2 percent were African-American. The race was unknown for 11 percent of offenders, and other ethnic groups and races accounted for the remaining incidents.
There were 105 anti-Islamic incidents reported in 2008, about one-tenth the amount of anti-Semitic incidents, which totaled 1,103 in 2008, according to the agency.
President Obama recently signed an expansion of the federal hate crimes law to include crimes based on gender or sexual orientation.
Gay rights activists in Puerto Rico, a U.S. territory, are asking authorities to investigate whether the slaying of a gay teenager there this month was a hate crime. If the case is prosecuted as a federal hate crime, it is believed it would be the first such case under the latest addition to the law.
We have to prosecute each hate crime to the fullest extent of the law, but we also need to get at the roots," said Joe Solmonese, president of the Human Rights Campaign, in a statement responding to the report. The organization describes itself as the nation's largest gay, lesbian, bisexual and transgender civil rights organization.
"When we don't know each other as human beings, ignorance breeds misunderstanding, which breeds hate, which too often this year led to violence," Solmonese said. "We have to keep fighting the prejudices and stereotypes that underlie these acts."
CNN's Arthur Brice and Terry Frieden contributed to this report.