International aid agency Action Against Hunger said on Thursday that a staff member and five others kidnapped in Nigeria last week had appeared in a video released on Wednesday evening.

The people, abducted last week near the town of Damasak in northeast Nigeria, are “apparently in a good condition of health”, the aid group said in a statement.

No group has claimed responsibility for the abduction, in which a driver was killed, but sources told Reuters it was carried out by Islamist insurgents. Two main groups operate in the region, Boko Haram and Islamic State’s West Africa branch.

All six abductees are Nigerian, sources said.

“Action Against Hunger strongly requests that our staff member and her companions are released,” said the agency.

The video was published by The Cable, a Nigerian news organization, and showed a woman sitting on the floor who identifies herself as “Grace”. Five men sit around her, some with their heads bowed. Behind them is a sheet with the logo of the United Nations refugee agency UNHCR.

“We were caught by this army called the Calipha,” she said, before asking that the Nigerian government and Action Against Hunger secure their release. “We don’t know where we are.”

The abduction comes nine months after Islamic State’s West Africa branch executed a Red Cross aid worker who was kidnapped from another town in northeastern Nigeria in March 2018.