Secretary of State Colin L. Powell said yesterday that a State Department report claiming a global decline in terrorist incidents last year was "a big mistake," but he said there was no intent to "cook the books" for political purposes.

Powell said during appearances on Sunday talk shows that the State Department was working over the weekend with the CIA to determine what went wrong, and he plans to meet with officials on the issue today.

"It's a numbers error," Powell said on ABC's "This Week." "It's not a political judgment that said, 'Let's see if we can cook the books.' We can't get away with that now. Nobody was out to cook the books. Errors crept in."

The "Patterns of Global Terrorism Report," released in April, had said that the number of terrorist incidents worldwide had dropped last year to 190, which would have been the lowest level in more than three decades and a decline of 45 percent since President Bush took office in 2001.

But State Department officials conceded last week that the report was in error, in part because it omitted acts of terrorism after Nov. 11, 2003 -- including a suicide bombing in Istanbul that killed 61 and injured more than 700. The original report's accuracy had been challenged by Rep. Henry A. Waxman (D-Calif.), and the Congressional Research Service urged a review of the report's "structure and content."

The complaints about the terrorism report are the latest in a series of controversies over the accuracy of information compiled and distributed by the U.S. intelligence community, including ongoing debate over faulty reports of weapons of mass destruction in Iraq. Bush administration officials, including Deputy Secretary of State Richard L. Armitage, had praised the State Department terrorism report as evidence of the country's progress in the war on terrorism.

Powell indicated yesterday that the information contained in the report was compiled by the Terrorist Threat Integration Center, a newly formed clearinghouse that is run by the CIA. Powell said problems with the data include the November cut-off date -- which officials have previously attributed to a printing deadline -- and differences in the way that "insignificant events" were counted from previous years.

"We are still trying to determine what went wrong with the data and why we didn't catch it in the State Department," Powell said on "This Week," adding: "It's a very big mistake and we are not happy about this mistake."