The Catholic Archbishop of Jos, in central Nigeria, has accused the West of ignoring the threat of the militant Islamist group, Boko Haram.
Ignatius Kaigama said the world had to show more determination to halt the group's advance in Nigeria.
He said the international community had to show the same spirit and resolve it had done after the attacks in France.
His warning came after 23 people were killed by three female suicide bombers, one reported to be 10 years old.
The weekend attacks come after reports that hundreds of people were killed last week during the capture by Boko Haram of the town of Baga in Borno state.
Archbishop Kaigama told the BBC's Newsday programme that the slaughter in Baga had shown that the Nigerian military was unable to tackle Boko Haram.
"It is a monumental tragedy. It has saddened all of Nigeria. But... we seem to be helpless. Because if we could stop Boko Haram, we would have done it right away. But they continue to attack, and kill and capture territories... with such impunity," he said.
The UN Secretary-General, Ban Ki-Moon, said he was appalled by reports of the killings in Baga and condemned what he called "the depraved acts of Boko Haram terrorists".
The Nigerian military has said it is trying to retake the town but has given few details about the operation.
On Saturday, it said it had successfully fought off Boko Haram fighters trying to capture another major north-eastern town, Damaturu.
A BBC correspondent in Lagos, Will Ross, says it was a rare success for the army, which on the whole has failed to protect civilians from the relentless violence.
Our correspondent says Nigeria's politicians appear more focused on next month's elections and President Goodluck Jonathan has not commented on the recent violence.
On Sunday, two female suicide attackers killed
A day earlier, another young female suicide bomber, reported to be 10 years old, struck in the main city of north-east Nigeria, Maiduguri, killing at least 19 people.
Archbishop Kaigama said facing down Boko Haram required international support and unity of the type that had been shown after last week's militant attacks in France.
"We need that spirit to be spread around," he said. "Not just when it [an attack] happens in Europe, but when it happens in Nigeria, in Niger, in Cameroon.
"We [must] mobilise our international resources and face or confront the people who bring such sadness to many families."
In June, Britain said it would increase its military and educational aid to help Nigeria tackle Boko Haram.
The aid includes counter-insurgency training for troops, which is also being provided by the US military.
However, Nigeria has criticised the US for refusing to sell it weapons because of alleged human rights abuses committed by Nigerian troops.
Jos, where the archbishop is based, has a mixed population of Muslims and Christians and has faced attacks by Islamist militants, although it is some distance from Boko Haram's strongholds.
Last month more than 30 people were killed in twin bomb attacks on a market there.
Churches have also been targeted in what are believed to be attempts by the militants to foment religious tension.
A French-led initiative has called for Nigeria, Niger, Cameroon and Chad to contribute 700 troops each to a multinational force against Boko Haram, but no country has implemented the plan.
Niger has blamed Nigeria, saying it has not kept to commitments regarding its own troop levels.