Kabul, Afghanistan (CNN) -- NATO's International Security Assistance Force took issue Wednesday with a new United Nations report that says violence in Afghanistan has jumped in the past year.
The report, from U.N. Secretary-General Ban Ki-moon, says monthly security incidents in 2011 are up 39% over the same period last year.
It paints a very different picture than findings by ISAF, which has repeatedly said violence is down in the country.
"Following an initial evaluation, ISAF found (the U.N. report) inconsistent with the data that we have collected," ISAF said in a statement.
Earlier, an ISAF spokesman noted that there are "differences in reporting of security incidents."
ISAF only counts attacks initiated by insurgents, while the United Nations includes all incidents, ISAF spokesman Lt. Col. Jimmie E. Cummings said in a statement.
Also, the United Nations includes weapons cache finds, arrests, assassinations, intimidation, and some other events as "security incidents," which ISAF does not, Cummings said.
The U.N. report, dated September 21, found the monthly number of security incidents in Afghanistan decreased from June to August. At the end of August, the average monthly number of incidents for 2011 was 2,108.
Most of the incidents involved armed clashes and improvised explosive devices. There were just as many suicide attacks -- 12 per month -- as there were a year ago, the report said.
"The south and southeast of the country, particularly around the city of Kandahar, continued to be the focus of military activity and accounted for approximately two-thirds of total security incidents," the report said.
"Concerns about the protection of civilians increased with the rise in civilian deaths and injuries," the U.N. report said. It noted that the U.N. Mission in Afghanistan (UNAMA) documented 1,462 civilian deaths in the first six months of 2011, up 15% from the same period in 2010. Anti-government elements were responsible for 80% of the deaths, an increase of 28% over the same period in 2010.
"The increase can be attributed, in the context of overall intensified fighting, mainly to the use by anti-government elements of landmine-like pressure-plate improvised explosive devices and suicide attacks, in violation of international humanitarian law," the report said.
The report says it was being submitted to the U.N. Security Council in keeping with a Security Council resolution requesting that the secretary-general report on developments in Afghanistan every three months.
In a report in August, ISAF said that in 2011 it "has seen significant security improvements throughout Afghanistan," adding that "violence is down in 12 of the past 16 weeks as compared to the same period in 2010."
During the first six months of 2011, ISAF said, insurgents conducted approximately 20% fewer complex attacks than in 2010. The report, dated August 22, said civilian casualties were down "14% in the last three months, compared to the first three months of the year."
In an interview earlier this month with NATO TV, ISAF Cmdr. Gen. John Allen said "the gains are everywhere in some form or another, in terms of security" including "tremendous gains in the south in particular."
In that region, he said, the main effort "was to stop the insurgent momentum, the enemy's momentum. It has been stopped broadly and in many places it's been rolled back and what that has done is it's given the opportunity to cover ground that needed to be covered in terms of building and economic and governance capacity."
"While there have been what appear to be high-profile attacks that might have been successful, every one of those attacks has been put down by the Afghan National Security Forces which responded promptly and courageously and effectively," Allen said.
CNN's Josh Levs and Nick Paton Walsh contributed to this report.