LAGOS, Nigeria -- Several bombs in two locations of the Nigerian capital, Abuja, killed at least 15 people, the National Emergency Management Agency said Saturday.

The explosions Friday night were in Nyanya and Kuje, suburbs of Abuja, agency spokesman Sani Datti said in a statement. He said 13 people died in the blast in Kuje and two in Nyanya. At least 41 people were wounded, Datti said.

No group has claimed responsibility but the attack is similar to others by Boko Haram, Nigeria's home-grown Islamic extremist group. Boko Haram has largely been carrying out attacks in the country's northeast but has been extending its range to other cities.

Violence from Boko Haram's six-year insurgency has killed nearly 20,000 people and displaced 1.4 million from their homes. At least 1,000 people have been killed since President Muhammadu Buhari took office earlier this year with the promise of wiping out the insurgents.

Four suicide bombers killed at least 10 people Thursday in Maiduguri, the capital of Borno state, the army said. No group claimed responsibility but Nigerian security forces blamed Boko Haram, which is based in the area. At least 39 others were wounded in the attack in the Sareji neighbourhood of Maiduguri, military spokesman Col. Sani Kukasheka Usman said.

Nigeria's military on Thursday also accused Boko Haram of poisoning water sources in the northeastern Nigeria.

President Buhari Saturday condemned the attacks. "It is clear this battle is not ideological. It is between the forces of peace and order and the evil forces of murder and destruction," he said.

"What quarrel do they have with the good people of Nyanya motor park?" the president asked. "What issue do they have with innocent people in market places in Maiduguri, Yola and Kuje?"