Updated

Terror attacks worldwide more than tripled last year, with much of the increase traced to incidents in Iraq, according to government figures released Tuesday by a senior House Democrat (search).

Based on a briefing federal officials gave congressional aides, Rep. Henry Waxman (search), D-Calif., said there were about 650 significant terror attacks last year. He said that was more than three times the record 175 tallied by the government in 2003.

In a letter to Secretary of State Condoleezza Rice (search) that his staff circulated to the media, Waxman said the 2004 figure may be underestimated significantly. Many incidents that most Americans would regard as terror attacks were excluded from State Department data, he said, because they did not meet the department's definition.

Waxman has been critical of State Department reporting on terrorism. Last week he accused Rice of denying Congress and the public important information about the number of incidents.

"There appears to be a pattern in the administration's approach to terrorism data: Favorable facts are revealed while unfavorable facts are suppressed," Waxman said in a letter to the department's acting inspector general, Cameron R. Hume, demanding an investigation.

Last year, the department reported a decline in significant incidents of terror in 2003 and then issued a corrected report showing an increase. The falloff had been used by senior Bush administration officials to bolster President Bush's claim of success in countering terrorism.

State Department spokesman Adam Ereli said last week that the department is "committed to being responsive to Congress and to contributing to an informed public debate."

Waxman said Russ Travers, deputy director of the National Counterterrorism Center, told congressional aides during a briefing Monday that more than 100 attacks in Iraq were not counted because they were not considered to be international attacks.

In Iraq, Waxman said, where the United States is spending billions of dollars to restore order, there were nine times as many terror attacks in 2004 as there were in 2003.

The State Department is due to report to Congress and make public by the end of the month its annual account of terrorism around the world.

The department announced last week it had decided to stop publishing an annual statistical account of incidents, turning the task over to the counterterrorism center, which Congress established last year.