Scenes of chaos spread across Pakistan ahead of Benazir Bhutto’s funeral on Friday as her enraged supporters torched cars, ransacked banks and burned effigies of Pervez Musharraf, the US-backed military ruler.

The violence came as Pakistani authorities claimed evidence of al-Qaeda involvement in the opposition leader’s assassination on Thursday. Although unsubstantiated, the suggestion alone raises fresh concerns about one of the international community’s central fears that the possible collapse of the state could see extremists getting control of the nation’s nuclear arsenal.