News services Fides says Muslim terrorist group Boko Haram has been carrying out attacks in the Diocese of Maiduguri, in the north of the country.
According to reporters in the area, 11 cities there have fallen to the extremists.
Local Bishop, Mgr Oliver Dashe Doeme, said: "It is over 30 days now that our church communities in Gulak, Shuwa, Michika, Bazza (among others) were sacked by the callous attacks of the Boko Haram terrorists.
"Gwoza and Magadali had been under the tyrannical and despotic control of the terrorists and this is almost the 60th day.
"Our priests are displaced, while citizens, who were supposed to celebrate their independence as a free nation, were rather counting their losses and regrets as they had been reduced to the status of internally displaced persons (IDPs). Where is the freedom?"
Boko Haram has been carrying out attacks in Nigeria and Cameroon while both countries' armed forces struggle to contain the group.