Shaikh said that Alqaeda is a Takfiri organization (Takfir means considering all other Muslims kafir who not support your thinking and agenda) and involved in killings of thousands of Muslims. while Islam not allows killing any innocent human being.
I will now like to talk something about Takfir. Takfir is not a new thing. in history as well Takfri groups existed who considered others Muslims kafir and right to kill them. at present as well some such groups exists like Alqaeda and Hakeemullah Mehsud group in Waziristan. Hakeemullah group has killed thousands of Pakistani Muslims in last three year. May Allah Swt give them Hadaya and show them right path the path of Mustaqeem.