Release International is calling on the international community to help protect Christians in Nigeria after a second deadly attack near Jos.
At least 12 Christians were killed in Byei and Baten villages on Wednesday, little more than a week after a massacre on the Christian community in which as many as 500 people were killed by members of the Muslim Fulani tribe.
Victims of the latest attack included two pregnant women and children. According to Release International, attackers burned a mother and her two children to death and cut out the tongues of some victims.
"This is the second appalling attack on Christians in this area in a fortnight," said Andy Dipper, head of Release International, which serves the persecuted church. "Release calls on Nigeria to act decisively to restore order and to protect its citizens.
"And we call on the international community to make sure that security is restored."
The attacks have taken place despite a curfew and the deployment of military personnel and police to keep the peace. Christian Solidarity Worldwide Director Stuart Windsor expressed concern over reports that some of the attackers were wearing military uniforms.
"The fact that these latest attackers were allegedly in military attire begs serious questions over whether army units currently stationed in Plateau State are truly capable of providing protection," he said.
"We call on the federal government to initiate an immediate review of the army's continuing failure to provide adequate safety for vulnerable Nigerian citizens, and to urgently investigate allegations of complicity on the part of elements of the armed forces."
Brigadier General Donald Oji told reporters that seven of the assailants had been arrested, while troops were tracking down other suspects.
He said a number of weapons were retrieved, including guns, bows and arrows, machetes, knives and cutlasses.
The killings have been condemned by State Governor Jonah Jang, who alleged that some people were attempting to fuel misunderstandings among the local Muslim and Christian communities, according to Compass Direct News.
"It gets to a stage when one remains strong, but when you receive the news of fresh attacks, you get broken before you recover again," he said.
"I have total faith in God because I am a child of God; and because I know there is nothing that happens that God is not aware particularly when it happens to His children. I have talked to God that whatever sin we have committed on the Plateau He should have mercy on us."
Jos, which lies between the largely Muslim north and the mainly Christian south, has been a flashpoint for religious tensions since attacks on Christian communities began in 2001. Release International said there had in recent years been an increasing polarization between different ethnic groups.