At least 46 "severely injured" people remain in a refugee camp that Nigeria's military says it mistakenly bombed and they need urgent evacuation, the International Committee for the Red Cross said Wednesday.

"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 told The Associated Press that more than 100 refugees and aid workers were killed in Tuesday's bombing in a remote northeast region near the border with Cameroon. The Red Cross statement said an estimated 70 people were killed, plus at least six aid volunteers.

Nigeria's military said it had been trying to target Boko Haram extremists. It is believed to be the first time Nigeria's military has acknowledged making such a mistake in a region where villagers have reported civilian casualties in near-daily bombings targeting the Islamic militants.

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.

At least 90 patients remained in Rann, the community where the bombing occurred, the Red Cross said. Nine patients in critical condition had been evacuated by helicopter to the northeastern city of Maiduguri.

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.

Calling the bombing accidental doesn't mean victims should be denied compensation, Segun said.

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.

The humanitarian crisis created by the insurgency in Nigeria's northeast has been called one of the worst in the world, and it has crossed into neighboring countries. Boko Haram's uprising has killed more than 20,000 people and forced 2.6 million from their homes, with the United Nations warning more than 5 million people face starvation.