The Central Mosque is close to the Emir of Kano’s palace and is where the influential Muslim leader usually leads prayers.
The Emir, Muhammad Sanusi, is currently in Saudi Arabia.
An eyewitness said he had counted about 50 bodies, but this figure has not been verified.
Other reports say some gunmen went on a shooting spree in the northern city after the blasts.
The militant Islamist Boko Haram group has targeted the city, the largest in northern Nigeria, several times during its five-year insurgency.
But most of its attacks are further east.
Earlier this month, the Emir called on people to defend themselves against Boko Haram.
At a prayer meeting Muhammad Sanusi said residents should “acquire what they need” to protect themselves.
A police spokesman said the Emir’s comments were a “call for anarchy” and should not be acted on.
The Emir, who until earlier this year was governor of Nigeria’s central bank, normally stays silent on political matters.
Image source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…