The number of hate crime incidents against people of different races, religion and sexual orientation reached 7,783 in 2008, according to data released by the U.S. Federal Bureau of Investigation.

That's an increase of two per cent from the 7,624 incidents reported by law enforcement agencies around the country in 2007.

However in its release Monday, the FBI cautioned against drawing conclusions from the new figures because the number of agencies that report to the bureau varies from year to year. Furthermore, the FBI added, the increase reported Monday might well be due to more agencies tracking such incidents.

In 2008, 2,145 different agencies reported hate crimes, while the year before 2,025 agencies did this reporting.

Half of all hate crimes last year were racially motivated, according to the FBI. One in five was driven by religious bias, and 17 per cent was based on sexual orientation bias.

Brian Levin, director for the Center for the Study of Hate and Extremism at California State University-San Bernardino, warned that the statistics may be misleading because some states, such as California, New Jersey, and Ohio, are good at reporting hate crimes while others, such as Georgia, Hawaii, Mississippi and Pennsylvania, are not.

"The quality of the data is so variable and in some instances so bad that it makes trend analysis extraordinarily difficult, if not impossible," Levin said. "Generally, states that have effective data collection also have effective training and procedures to address these crimes."

Joe Solmonese, president of the U.S.'s largest gay civil rights group, Human Rights Campaign, called the figures unacceptable and said they showed the need for the expanded federal hate crimes law.

Last month, U.S. President Barack Obama signed a bill expanding those covered by the federal law against hate crimes. Previously, the law had protected those attacked on the basis of race, color, religion or national origin.

The new law now covers crimes based on gender, sexual orientation, gender identity or disability. It also removes the restriction that federal authorities can launch investigations of victims who were engaged in federally protected activities such as voting or free speech.

With files from The Associated Press