At least 56 people have been killed in an air strike on a camp for internally displaced people in Ethiopia’s northern region of Tigray, according to Reuters.

There were at least 30 others injured in the bombing on Friday night, two aid workers told the news agency, citing local authorities and eyewitness accounts.

The workers sent Reuters pictures of people wounded in hospital, including many children.

One of them visited Shire Shul General Hospital, where the injured were treated, and said the camp hosts many old women and children.

“They told me the bombs came at midnight,” the worker said. “It was completely dark and they couldn’t escape.”

The government has been accused of targeting civilians in the 14-month conflict with rebellious Tigrayan forces – which it has previously denied.

Military spokesman Colonel Getnet Adane and government spokesman Legesse Tulu did not immediately respond to requests for comment.

The aid workers, who asked not to be named because they did not have permission to speak to the press, said the number of casualties was confirmed by local authorities.

The camp that was hit by the strike is in the town of Dedebit in the northwest of the region, near the border with Eritrea, they said.

The attack comes after the government pledged to begin dialogue with political opponents, with the state-run broadcaster reporting on Friday that several opposition leaders had been released from prison.

Some leaders of the Tigray People’s Liberation Front (TPLF), the party fighting Prime Minister Abiy Ahmed’s government, were reportedly among those freed.

The move was hailed as the most significant breakthrough since the war in Tigray began.

“The key to lasting peace is dialogue,” a statement from the government communications office said. “One of the moral obligations of a victor is mercy.”

UN Secretary-General Antonio Guterres had said he welcomed “meaningful improvement in humanitarian access to all areas affected by the year-long conflict”.