The US-led military command in Afghanistan has acknowledged that its report of a 7% decline last year in Taliban attacks was incorrect.
Officials say corrected figures will show no decline.
After finding what they are calling clerical errors, military officials in Kabul are preparing to publish corrected numbers that some may see as undercutting their narrative of a Taliban insurgency in steep decline.
A 7% drop in "enemy initiated attacks" for the period from January through December 2012 that the International Security Assistance Force, or ISAF, had reported last month is being corrected to show no decline in attacks, officials said.
ISAF spokesman Jamie Graybeal said a quality control check found that some data had been incorrectly recorded.
He said a portion of the data from unilateral Afghan military operations was "not properly reflected" in the trends ISAF had reported.