That's about five times as many incidents as the 651 counted using a different measure for the year. The information, updated to include data tracked until Tuesday, reveal that nearly 29,000 people were affected by terror — they were either killed, injured or kidnapped. Nineteen percent of the attacks were committed by Islamic extremists.
Of the total, incidents in Iraq accounted for 27 percent of the terror in the world, including five of the 10 largest terrorist attacks in 2004. In several cases, those involved attacks on police recruits.
The new database is "the most comprehensive U.S. effort to date to track terrorist incidents worldwide," Brennan said.
When the NCTC first released its report in April, a lot of controversy surrounded the way in which terrorism incidents were counted. Brennan said that the apparent surge should not suggest to people that the United States is losing the War on Terror. Instead, he said more analysts are counting the attacks and the criteria for what constitutes an attack has broadened. The different methodology for counting events makes comparison of prior records-keeping impossible, he said.
For example, unlike in previous years, the NCTC has included incidents in which terrorists attacked civilians in their own country and no other nationals were involved. Under the old definition, a terrorist attack had to include property or individuals from more than one country. That meant a ferry attack in February 2004, in which more than 100 people were killed by an Al Qaeda (search)-related grou, was not included because only one nationality, Filipino, was involved.
The definitions can be tricky. The data do not include attacks on U.S. military personnel in Iraq by foreign fighters, because it is considered a war zone and U.S. personnel are "combatants." It does include attacks by foreign fighters on Iraqi police officers who are not considered combatants.
But the increase, no matter how it's defined or explained, may provide fodder for critics who argue that Iraq, which under the new data experienced 866 attacks in 2004, has become a breeding ground for Islamic extremists, who take the training and skills honed there to launch attacks outside the country.
FOX News' Catherine Herridge contributed to this report.