"A video recording of their plea for intervention" surfaced earlier this month, the Salkdia report said, adding that they had pleaded with Nigerian President Muhammadu Buhari and the leadership of the Christian Association of Nigeria for their rescue.
A masked man in the nearly one-minute video claimed the killings were in response to the death of ISIL chief Abu Bakr al-Baghdadi and his spokesman.
Islamic State militants in Nigeria have executed 11 Christian captives to coincide with Christmas celebrations, claiming the killings as revenge for ISIS leaders assassinated by USA forces this year. A video showing a group pleading for help was released by the terrorists earlier this month.
IS said it was part of its revenge against the killing of its leaders after failure to negotiate their release.
The clip released on December 17 appears to show 12 men and one woman sitting on the ground.
However, the United Nation's Secretary General Antonio Guterres has commiserated with Federal Government and Nigerians over the killings of the civilians.
Not a lot of details were given about the victims other than they were male, Christian and "captured in the past weeks" in Nigeria's north-eastern Borno State. Islamist insurgents have killed about 30,000 people in northern Nigeria in the past decade. "He expresses his deepest condolences to the families of the victims and reiterates the solidarity of the United Nations with the people and Government of Nigeria", a December 24 statement said.
The group raided a Christian village near the town of Chibok, in Borno state where more than 200 female students were abducted by Boko Haram in 2014.
"We killed them as revenge for the killings of our leaders, including Abu bakr al-Baghdadi and Abdul-Hasan Al-Muhajir in Iraq and Syria", the group was quoted to have said.
"This is a message to Christians all over the world", a masked man says in the one-minute video posted online late Thursday by the terror group's Amaq news agency.
"As Prime Minister, that's something I want to change".