Tens of thousands have rallied in Pakistan's largest city in support of a 14-year-old girl shot and critically wounded by the Taliban for promoting girls' education and criticising the militant group.

The demonstration in the southern city of Karachi today was the largest by far since Malala Yousufzai and two classmates were shot October 9 while returning home from school.

The rally was organised by the most powerful political party in Karachi, the Muttahida Quami Movement.

The party's chief, Altaf Hussain, addressed the audience by telephone from London, where is he in self-imposed exile.

Mr Hussain called the Taliban gunmen who attacked Yousufzai "beasts" and said the shooting was an attack on "the ideology of Pakistan".

The demonstrators carried the young girl's picture and banners praising her bravery.