Lagos, Nigeria (CNN) Two bomb attacks in 24 hours -- one of them involving an 11-year-old female bomber -- killed dozens of people and wounded more than 120 others in the Nigerian cities of Yola and Kano, authorities said.

At least 31 people were killed and 72 others injured in a bomb blast Tuesday evening in the northeastern city of Yola, Aliyu Maikano, a local Red Cross official, said.

It was not clear whether the blast was from a planted device or the work of a suicide bomber, according to reports.

An official from the National Emergency Management Agency (NEMA), Sa'ad Bello, gave a slightly higher toll of 32 dead and 80 injured, while hospital officials gave newspapers an even higher total.

Roughly 400 miles to the northwest, in Kano, two bombings killed 15 people and injured at least 123 in a mobile phone market, Kano state police commissioner Muhammad Musa Katsina said.

'The most deadly terrorist group in the world'

The two bombers, who Katsina said were females ages 11 and 18, blew themselves up at about 4 p.m. local time, during the peak of trading, he said. A minivan carrying four other children believed to be bombers dropped the girls off, he said.

Police searching for the minivan set up checkpoints around the city and along its outskirts. Armed policemen conducted searches on motorists entering the city.

No group has claimed responsibility for the attack, but Boko Haram, a militant Islamist group, is the prime suspect. The terrorist outfit hit the same market in January 2012, killing 185 people in bomb and gun attacks there.

Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world, according to the Global Terrorism Index 2015, compiled by the Institute for Economics and Peace. Boko Haram has pledged allegiance to ISIS.

"Also notable over the past year is the major intensification of the terrorist threat in Nigeria," the report said. "The country witnessed the largest increase in terrorist deaths ever recorded by any country, increasing by over 300% to 7,512 fatalities."

Yola blast

ripped through the crowded Tipper Garage in the Jambutu area of the city at about 7:48 p.m., ‎shortly after evening prayers, Maikano said. The blast came almost a month Tuesday evening's explosionripped through the crowded Tipper Garage in the Jambutu area of the city at about 7:48 p.m., ‎shortly after evening prayers, Maikano said. The blast came almost a month after a deadly mosque attack in the same area.

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"I cannot say how many people died in the explosion, but human parts littered the place. It happened when traders were closing shop for the day," a resident identifying himself only as Mustapha told the Nigerian newspaper, Punch

The area houses a livestock market, an open-air restaurant and a mosque. The explosion happened as traders were leaving the mosque and others were eating at the restaurant.

Relatives of those who worked in the area converged on Specialist Hospital Yola to determine whether their loved ones had been admitted, according to state-run Nigerian media.

"Since I did not see my brother who was selling sugar cane at the scene of the incident, I have no option but to come to the mortuary," a man named Adamu told the News Agency of Nigeria

"The enemies of humanity will never win. Hand in hand, we will rid our land of terrorism." ~ Pres @MBuhari — President Buhari (@NGRPresident) November 17, 2015

The hospital had received 29 bodies from the explosion, chief medical director Bala Sa'id told NAN. Thirty people, including six women and eight children, had been admitted with injuries, he said.

The Yola Federal Medical Centre received 37 injured people and four bodies, spokesperson Malam Adamu Dodo said, according to NAN.

Nigerian President Muhammadu Buhari visited Yola five days ago to present medals to soldiers fighting Boko Haram militants, as well as a camp for people displaced by the conflict. Buhari declared that the terror organization was close to defeat, according to the Daily Independent , an Ogba-based newspaper.

Buhari urged soldiers "to remain vigilant, alert and focused to prevent Boko Haram from sneaking into our communities to attack soft targets," the paper reported.

No one has yet claimed responsibility for the blast, but clearly, experts on the group believe Boko Haram operatives should top the list of primary suspects.

"Boko Haram has always shown the intent and operational capacity to carry out attacks such as these," said Ryan Cummings, chief Africa analyst for the crisis managment company, red24. "Yola has traditionally been an operational stronghold of the group and they have also had an established presence in Kano for some time. Can we draw parallels to what is going on in Paris and this? Likely. Boko Haram is likely to take advantage of the public relations aspect to gain some attention through attacks in its own territory."