Shaikh Abdullaah Al-Bukhaari (may Allaah preserve him) said:

He (rahimahullaah) established an institute called [(المعهد الشرعي لإعداد الدعاة] in Peshawar.  A number of callers (to Islaam) studied in this institute and its aim was to furnish callers (to Islaam) with sound knowledge of the sharia founded upon the Qur’aan and the Sunnah, and the affair was just as he (rahimahullaah) wished. And from the efforts of the institute was the publication of Salafi Books and included amongst them were: [منهج و دراسات لآيات الأسماء والصفات] of Imaam Muhammad Al-Ameen Ash-Shanqeetee (rahimahullaah); [أصول في البدع والسنن] of Al-Allaamah Muhammad Ahmad Al-Adawi (rahimahullaah)—a beneficial and good treatise; and also the book of Al-Allaamah Muhammad Sultaan Al-Ma’soomee Al-Makki (rahimahullaah) titled: [هل المسلم ملزمٌ باتباع مذهب معين من المذاهب الأربعة], and many other books besides them.

All this effort infuriated Ahlul Bidah amongst the hizbiyyeen (i.e. those particular hizbiyyeen at the time) and those affiliated with them; so they pondered, contemplated and masterminded his killing. They embarked upon that which gives a clear indication of their malicious intentions and rage against the Sunnah and its people—those who defend the Sunnah.  They waged war against the caller to Tawheed and Sunnah—the one who erected the true flag of Jihaad [i.e. during the Soviet-Afghan war -1979-1989].  So they besieged Sheikh Jameel and surrounded his people, and they sought the aid of the bad, aggressive and deadly people, and every vandal and destructive person—and all this was for the purpose of putting an end to the banner (i.e. the call) to Tawheed and the Sunnah!! Then take admonition, O you with eyes (to see)!

[Slightly Paraphrased, see link: http://www.elbukhari.com/node/31]