Get all the latest updates from the war in Afghanistan on the Afghanistan Crossroads blog.
(CNN) -- The insurgency in Afghanistan is gaining strength and new recruits in areas where the Taliban has not previously been prominent, according to a new report from the Afghanistan NGO Safety Office (ANSO) in Kabul.
In the third quarter of this year, it says, armed attacks by insurgents were 59 percent higher than in the same period of 2009.
The gloomy assessment of the security situation says some districts in northern provinces are in danger of slipping beyond control, and it describes efforts to form local militias in opposition to the Taliban as "clumsy."
It recommends that nongovernmental organizations engage with insurgent groups rather than avoid them.
There is evidence that insurgents are ready to accommodate nongovernmental organizations, according to the report.
The ANSO director, Nic Lee, writes that counterinsurgency efforts in Kandahar and Marjah in the south "have failed to degrade [insurgents'] ability to fight, reduce the number of civilian combat fatalities or deliver boxed government."
NATO said earlier this year that as part of its plan to secure Marjah, it planned to inject government services rapidly -- a plan dubbed by then commander U.S. Gen. Stanley McChrystal as "government in a box."
The new report says that insurgents are now operating advanced administrations in the south and east, and field reports suggest that insurgents are attracting non-Pashtun support in the north from elements within the Turkmen, Uzbek and Tajik communities.
The Taliban is predominantly made up of Pashtuns, the largest ethnic group in Afghanistan.
Within this environment, the report says, nongovernmental organizations are taking ever more precautions, and deliberate attacks on aid workers by insurgent groups have fallen this year.
Abductions of local nongovernmental organizations employees -- especially in the north -- have risen sharply, but all have been released. It says 25 workers have been killed in the first nine months of this year, compared with 17 in the same period last year.
However, this year's death toll includes the killing of 10 aid workers -- including eight foreigners -- in one attack in the far north-east of Afghanistan in August. The Taliban at first claimed responsibility for that attack but later denied being involved.
The most striking statistic produced by ANSO concerns the number of attacks by "armed opposition groups" this year.
After falling in the months following the presidential election in August 2009, it began climbing from 523 in February this year to a record high of 1,483 in September. ANSO says September's high was largely due to the parliamentary elections, but sees a consistent pattern over the past five years, with attacks rising 45 to 55 percent year on year.
It concludes that the growth in insurgent activity may be in part a response to the increase in NATO operations, especially in the south. But the report notes that many of the provinces showing the sharpest increases are in the east and north.
ANSO advises nongovernmental organizations on safety conditions in Afghanistan.