The organisation in a statement by Osai Ojigho, Director of Amnesty International Nigeria, on Friday, said it analysed satellite imagery which showed hundreds of burned structures in the town.
According to Ojigho, many of the destroyed structures only date back to 2017, suggesting they were shelters for Internally Displaced People (IDPs) who came to Rann seeking protection.
Ojigho said: “We have now confirmed that this week’s attack on Rann was the deadliest yet by Boko Haram, killing at least 60 people.
“Using satellite imagery, we have also been able to confirm the mass burning of structures as Boko Haram unleashed a massive assault on Rann, most of which is now destroyed.”
Ojigho added, “This attack on civilians who have already been displaced by the bloody conflict may amount to possible war crime, and those responsible must be brought to justice.
“Disturbingly, witnesses told us that Nigerian soldiers abandoned their posts the day before the attack, demonstrating the authorities’ utter failure to protect civilians.”
Amnesty International disclosed further that alleged withdrawal of troops triggered a massive exodus of civilians to Cameroon, as fear spread that Boko Haram would take advantage and attack the town.
It said a group of Boko Haram fighters arrived on motorcycles at around 9am on 28 January and set houses ablaze while those left behind were killed.
The group said the terrorists also chased after those who attempted to escape and killed some people outside the town, noting that 11 bodies were found within Rann while 49 others were found outside.
According to the statement, it was informed that about 50 people have not been accounted for and those who took part in the burial explained what they saw.
“Ten of us [Civilian Joint Task Force] came from Cameroon to Rann for the burial,” an eyewitness was quoted as saying. “When we arrived, we found and buried 11 corpses within the town, but the soldiers told us that they buried several others yesterday [30 January] who had decayed.”
“Outside the town, we recovered and buried 49 dead bodies all with gunshot wounds,” the witness added
Aid agencies, according to Amnesty International, reported that some 30,000 civilians have fled for the border with Cameroon in recent days, joining a further 9,000 who fled previous Boko Haram attack on Rann on 14 January.
Amnesty International analysed satellite images from Wednesday, showing hundreds of structures burned in the east, south and southeast of Rann.
According to it, environmental sensors detected fires in the area on Monday and Tuesday.
The group revealed that in the 14 January attack, Boko Haram burned well over 100 structures in other areas of Rann, stressing that the two recent attacks have left most of the town heavily damaged or destroyed.
Amnesty International, therefore, called on the Nigerian authorities to investigate the alleged withdrawal of security forces of the Multi-National Joint Task Force (MNJTF) from Rann, which it said may have left tens of thousands of civilians exposed to the latest deadly attack.
“Boko Haram has consistently and deliberately targeted civilians in Rann, which makes the Nigerian authorities’ failure to protect people all the more unacceptable,” said Ojigho.
She added, “The authorities on both sides of the border must provide the supplies and safety that these people require.
“The Cameroonian authorities must also desist from forcing people to return until conditions are safe and they choose to do so voluntarily.”