The attack took place near the Hockey Field on Zoo Road by Total Gasoline station when the Emir was returning from the inauguration of an Islamic school at Mussalaci Murtala.
The News Agency of Nigeria reports that the Emir was unhurt in the attack and was moved to an undisclosed location.
Some residents in the area said men of the Joint Task Force later got to the scene of the attack and shot sporadically.
JTF spokesperson in Kano, Captain Ikedichi Iweha, said he was still trying to get the full details of the attack for him to release an official incident report.
However, Kano State Governor, Rabiu Kwankwaso, confirmed that four people died during the attack.
Meanwhile, the Deputy Chairman, National Union of Road Transport Workers in Oyo State, Mr. Kamorudeen Beyioku, died on Saturday while receiving treatment at the University College Hospital, Ibadan.
Beyioku was shot earlier in the week by unknown gunmen.