Because the gunmen are reported to have fled on the back of motorbikes, Kanostate has banned such machines, known as "achaba", from being used as taxis.
The emir's convoy was attacked by unknown gunmen as he was returning from Koranic graduation ceremony in Kano city, Kanostate governor Musa Rabiu Kwankwaso told AFP news agency.
On his private jet, the Nigerian billionaire Aliko Dangote - whose business empire includes production of cement, flour and sugar - explained why he is involved in an initiative to double immunisation efforts in his home state, Kano.