In an attack the Vatican described as the work of “blind and absurd hatred”, 35 Christians were killed on Christmas Day in Madalla, near the capital Abuja.
Eye-witnesses said an attacker threw a bomb into or next to Saint Theresa Church.
A second similar attack targeted an evangelical church in Jos. The policeman guarding the church was killed.
Three other explosions were reported in Gadaka and Damaturu in Boko Haram’s fiefdom of Yobe State.
An RFI correspondent in Damaturu said people were “devastated” by the bombings.
Speaking of the "fear and anger" of local people, he said commercial activity had been brought to a standstill, compounding poverty in an already very poor region.
There is now concern, he said, that people would simply move away if this violence continues leaving an economic wasteland behind them.
The Christmas Day massacres follow a week of clashes between Boko Haram and the army and police in North-East Nigeria in which 70 people are believed to have died.
In June, the group announced that some of its fighters had been trained in Somalia by a group linked to Al-Qaida.
The Malian Foreign Ministry says a hundred Boko Haram members, “half of whom are bombers”, were trained by Al-Qaida in the Islamic Maghreb.