Lieutenant Ikedichi Iweha, a spokesman for the Military Joint Task Force, said earlier that 12 people died at the scene and "a couple" of people were wounded in Monday night's attack, which he blamed on suspected members of the Islamic extremist Boko Haram network.
But the spokesman for Aminu Kano Teaching Hospital said its mortuary had 24 bodies brought from the scene. The teaching hospital also was treating nine people wounded in the blasts, said spokesman Aminu Inuwa.
Another 11 victims were being treated at Murtala Muhammad Specialists Hospital.
Printer Ezekiel Alade, 47, said he heard "a deafening sound" and was injured by two of the blasts.
"A sharp object pierced through my left hand and blood gushed out," he said. "Then, another bomb exploded and, before I could escape, another object pierced into my leg."
He was trying to crawl to safety when a soldier saved him.
Kano state governor Rabiu Musa Kwankwaso visited Alade and other victims on Tuesday.
He described the explosions as "an attack on Nigeria because Muslims and Christians" and people of various tribes all lost their lives or were injured.
More than 100 people gathered outside the Aminu Kano hospital morgue, weeping and screaming in anguish.
Nigeria is fighting an uprising by Islamic extremists based mainly in the northeast, where the government has declared a state of emergency. Kano city and state are in the northwest and not part of that emergency.
Boko Haram, which means "Western education is forbidden," wants to impose Islamic law in all of Nigeria.
With more than 160 million people, Nigeria is Africa's most populous nation, and it is divided almost equally between Christians who live mainly in the south and Muslims who dominate the north.
Nigeria's army announced on Tuesday it has arrested 42 suspected Boko Haram members in the southwestern states of Ogun and Lagos, which includes the commercial capital of the same name.
Major General Obi Umahi told reporters that some of those detained already have admitted to belonging to the extremist network.
He said some said they had fled from strongholds in the northeast of the country that are under a state of emergency and military operations.
Boko Haram has never attacked targets in the southwest of the country.
Umahi said some suspects were arrested in Lagos on upscale Victoria Island's Bar Beach and in the Lekki neighbourhood. The arrests were made between July 12 and 23.
