These are mosques frequented by Shia Houthi rebels who booted the government out of Sanaa recently. The militant Islamic State based in Syria/Iraq claimed responsibility. Al Qaeda in the Arabian Peninsula could also have carried out the attacks.
Yemem has Shia in the north, near Sanaa and Sunni in the south around Aden. Iran backs the Houthi, the Gulf Emirates and Saudis back the Sunnis. To give you a flavor of the feelings there, here is what the Islamic State warned:
"Let the polytheist Houthis know that the soldiers of the Islamic State will not rest and will not stay still until they extirpate them," the group said in a statement posted by supporters on Twitter. "God willing, this operation is only a part of the coming flood.""Polytheist" is a very ugly insult to Muslims, who daily pray "there is no god but god." Allowing for the florid, over-the-top style in which Arabic is routinely constructed - Saddam's "mother of all battles" being a rout - those are still fighting words.
Agence France-Presse, aka AFP, reports via Yahoo News a few more killed, at 142, and includes details Reuters omits.
