Twenty-six people were killed and 28 injured Saturday afternoon in a suicide bomb attack inside a mosque in Maiduguri, the capital and largest city of Borno state, Aderemi Opadokun, the Borno State Police Commissioner told CNN.
Nobody has claimed responsibility for the attack, which occurred while worshipers were inside the mosque.
Earlier Saturday, the Islamist extremist group Boko Haram launched a rocket-propelled grenade attack on Maiduguri.
According to residents and military sources, the assault damaged to at least five homes and killed 13 people began just after midnight and lasted about three hours.
Hassan Buba, a local leader, said of the grenade attack: "Boko Haram
kept shelling the area with RPGs, ... Many people were also injured."
Malam Yusuf says his wife is one of them, in the hospital after one of her feet was blown off after their home in Maiduguri's Dala neighborhood was hit before dawn.
"It was deafening explosions all over, as volleys of RPGS were fired by Boko Haram from outside the city," Yusuf said by phone.
Two Nigerian military officers accused the extreme Islamist group of resorting to indiscriminate RPG attacks -- which pose as much, if not more, danger to civilians as anyone else -- because troops had repelled their attempts to enter and capture the capital city.
"It was an (act) of desperation," said one of the officers, who asked not to be named because he is not authorized to speak to the media. "... The attacks were ultimately neutralized, and the terrorists forced to retreat."
The assault came one day after two explosions ripped through a wedding ceremony in the Borno state village of Alade, about 140 miles (230 kilometers) from Maiduguri.
Seven wedding guests died and 30 others were injured in blasts at the start of the ceremony, said local leader Aisami Babagoni, who added that he suspects the explosives were planted ahead of time and "remotely detonated."
New president, same problem
Its name translates to "Western education is sin" in the Hausa language, but Boko Haram is hardly an education reform or advocacy group. It is a terrorist organization, according to the U.S. State Department
-- one that's shown little restraint against civilians and official authorities alike in a quest to impose its extreme version of Sharia law over an expansive territory.
Residents of Borno state and other parts of northeastern Nigeria know this all too well. For years they have dealt with Boko Haram assaults, bombings, abductions
and mass kidnappings -- the most infamous being the taking of more than 200 schoolgirls
in the town of Chibok in 2014.
Chad and Niger have stepped up their efforts
in recent months going after the militant group in areas that border those nations. Still, Boko Haram is mostly Nigeria's problem. Combating this insurgency is one of the main challenges facing Buhari, who took over from Goodluck Jonathan in the first peaceful transfer of power between Nigeria's rival parties since the end of military rule in 1999. Another is dealing with lingering fuel shortages
, a paradox for one of the world's largest oil producers.
"Insecurity, pervasive corruption, the hitherto unending and seemingly impossible fuel and power shortages are the immediate concerns," Buhari said in his inauguration address Friday. "We are going to tackle them head on. Nigerians will not regret that they have entrusted national responsibility to us."