KABUL, Afghanistan – The Haqqani insurgent network, based in Pakistan and with ties to al-Qaida, is suspected of being a driving force behind a significant number of the “insider” attacks by Afghan forces that have killed or wounded more than 130 U.S. and allied troops this year, American officials said Friday.

Until now, officials had said the attacks seemed to stem either from personal grievances against the allies or from Taliban infiltration. The Taliban has publicly claimed to be orchestrating the campaign to subvert the U.S.-Afghan alliance.

New data provided to The Associated Press this week also reveal that in addition to 35 U.S. and allied troops killed in insider attacks last year, 61 were wounded. Those included 19 in a single attack in the eastern province of Laghman on April 16, 2011, in which six American servicemen were killed. Thus far in 2012 there have been 53 killed and at least 80 wounded, the figures showed.