BEIRUT - Lebanese Shi'ite group Hezbollah said on Saturday 'takfiri groups' were responsible for a blast which killed the group's top military commander Mustafa Badreddine. 'Takfiri' is a word used by the group to refer to hard-line, armed, Sunni Islamist groups. Hezbollah announced Badreddine's death on Friday and a military funeral was held for him on the same day in the group's stronghold in southern Beirut.