In a brutal attack attributed to the African affiliate of Islamic State (ISIS), Boko Haram, a suicide bomber struck a church during prayers on Sunday in the Nigeria town of Potiskum.
The priest and four other Christians at prayer, including a mother and her two children, were murdered at the Redeemed Christian Church of God, witnesses and police told CNN on Monday.
No terror groups have yet to claim credit for the attack on Potiskum, the commercial center of Yobe state, but the methods and selection of a church as a target lead experts to believe Boko Haram was behind the blast.
Nigeria saw several other attacks on Sunday as well, focused on the central city of Jos. One explosion struck near the Yan-Taya mosque in the middle of a sermon on the Muslim fast month of Ramadan.
The major Baruchi Road in Jos was also hit by a bomb, in an area that is home to many Muslim families. A source in Plateau Hospital in Jos said at least 15 people were murdered in the attacks, and 20 others were wounded.
Jos is located between the mostly Christian and animist southern part of Nigera, and the Muslim majority in the north of the African state.
Boko Haram has often attacked Muslims it views as too "moderate," aside from its central focus of attacking all Western influences. It has often struck churches in the past, such as in June 2013 when it murdered over 50 people in a series of church attacks, after a November 2011 string of attacks on 11 churches.
The group shot up mosques and murdered 80 Muslims at prayer Wednesday in the remote town of Kukawa, located in northeast Nigeria.
US State Department Spokesperson John Kirby responded to the recent spate of Boko Haram attacks, saying, "the people of northern Nigeria deserve to live free from violence and from terror."
"The United States continues to provide counterterrorism assistance to help Nigerian authorities develop a comprehensive approach to combat the threat posed by Boko Haram."
Boko Haram joined ISIS in March, swearing allegiance to the brutal terrorist organization.