Injured people still stuck at bombing site
At least 46 severely injured people remain in a refugee camp that Nigeria's military says it mistakenly bombed.
According to the International Red Cross they need to be evacuated urgently.
"Patients are attended to in an open-air space in a precarious environment," the aid group's statement said, raising the possibility that the death toll could significantly rise.
A government official has said that more than 100 refugees and aid workers were killed in Tuesday's bombing in a remote north-east region near the border with Cameroon.
Nigeria's military said it had been trying to target Boko Haram extremists.
The Red Cross statement said the aid group was "shocked" by the deaths of civilians and six aid workers with the Nigerian Red Cross.
The group was part of a humanitarian effort to bring food to more than 25,000 displaced people, the statement said.
Human Rights Watch called on Nigeria's government to compensate the victims of the bombing, which hit a camp for people who had fled Boko Haram.
Even if the camp was not bombed intentionally, which would be a war crime, "the camp was bombed indiscriminately, violating international humanitarian law," Human Rights Watch researcher Mausi Segun said in a statement.
Nigeria's presidency said a delegation was on the way to Rann.
President Muhammadu Buhari recently announced that Boko Haram had been "crushed" and driven out of its strongholds, but attacks continue.
