Three bombers detonated their explosives outside a hall in Konduga, 38km from the Borno state capital Maiduguri, where football fans were watching a match on TV.
"The death toll from the attack has so far increased to 30. We have over 40 people injured," Usman Kachalla, head of operations at the State Emergency Management Agency (SEMA), said on Monday, according to Al Jazeera.