Islamic law carries a death penalty for heresy, so this kind of thing is going to happen when one Muslim group decides that another is not properly Muslim, or not Muslim enough.
“Twin blasts at mosque in northern Nigeria kill at least 24,” by Ibrahim Abdul’Aziz, Associated Press, May 1, 2018 (thanks to Robert):
YOLA, Nigeria (AP) — A pair of explosions killed at least 24 worshippers at a mosque in northeastern Nigeria, with many of the victims caught in the second blast while trying to flee, police said Tuesday.
The attack in Mubi town came a day after President Muhammadu Buhari met with U.S. President Donald Trump at the White House and discussed the threat from the Nigeria-based Boko Haram extremist group. Its fighters were quickly blamed for Tuesday’s blasts.
This is the second time in six months that dozens have been killed in an attack on a Mubi mosque. In November, a teenage suicide bomber attacked worshippers as they gathered for morning prayers, killing at least 50 people in one of the region’s deadliest assaults in years.
“As I am talking to you now, 24 persons are confirmed dead and the scene is cordoned off by anti-bomb squads and other security personnel,” said Adamawa state police spokesman Othman Abubakar.
One resident, Isa Danladi, said he had been about to leave his house near the mosque when he heard the blast.
“The mosque roof was blown off and the prayer was midway when the bomber, who was obviously in the congregation, detonated his explosives,” Danladi said. “This is obviously the work of Boko Haram.”…