A suicide bomber detonated his explosives outside a Nigerian mosque Saturday just hours after Boko Haram militants reportedly launched a grenade attack on civilian homes. The double explosions killed at least 30 people and injured dozens of others, the Associated Press reported.

Violence in the capital of Nigeria’s Borno state, Maiduguri, came just a day after the country swore in President Muhammadu Buhari, who defeated former President Goodluck Jonathan in March elections. At his inauguration, Buhari vowed to combat Boko Haram, the Nigerian terrorist group that has killed thousands since its inception.

While no one has claimed responsibility for the second attack, the largest city of the northeastern Nigerian state is the birthplace of Boko Haram. Buhari also promised to move the headquarters of the campaign against Boko Haram to Maiduguri to better fight the militants.

“Progress has been made in recent weeks by our security forces but victory cannot be achieved by basing the Command and Control Center in Abuja,” Buhari said in his inauguration speech in the capital Friday.  “The command center will be relocated to Maiduguri and remain until Boko Haram is completely subdued.”

The suicide attack killed at least 16 people, in addition to the attacker, most of whom were in the mosque for afternoon prayers. Dozens of others were injured, and an outside wall of the mosque was demolished, officials told the AP.

Earlier Saturday, Boko Haram militants armed with high-caliber guns and rocket-propelled grenades attacked a civilian area in Maiduguri, destroying at least five homes, killing at least 13 people and injuring several others, CNN reported.

"Each time they fired into the town, we saw bright sparkling flashes, which moved with great speed,” Mari Madu, a Maiduguri resident, told the AP. “One of the blasts shook my roof so badly that I thought it must have landed on my house."

Twin bombings were carried out in a smaller town in Borno Friday, killing at least seven people, Reuters reported.

At least 13,000 people have been killed and more than 1.5 million have been displaced in Nigeria in the six years since Boko Haram launched its campaign to create an Islamic state.