Thousands of people have fled into Cameroon from north-east Nigeria following violent attacks by a faction of the militant group Boko Haram, which looted and destroyed large parts of a major town.

More than 8,000 refugees have crossed the border into Bodo after the attacks on the Nigerian town of Rann on Monday, in which at least 10 people are thought to have been killed. Homes and humanitarian organisations’ buildings were burned down.

Médecins Sans Frontières (MSF) said it was preparing to help 15,000 people with food, water and medicine. The organisation released photos showing smouldering buildings that had been burned to the ground, and columns of fleeing people crossing a river, their few belongings balanced on their heads.

‘Rann was like a graveyard’: Médecins Sans Frontières nurse Isa Sadiq Bwala. Photograph: Silas Adamou/MSF

“What struck me when we arrived was the silence. Usually Rann bustles with life, but yesterday it was eerie and quiet, like a graveyard. The town has been devastated and I was devastated to see it,” said Isa Sadiq Bwala, an MSF nurse.

It was unclear which faction of Boko Haram was responsible, but some sources in the north-east said the attacks were the work of Abubakar Shekau, the militant behind the 2014 abduction of the Chibok girls, who later appeared dishevelled in a video released online vowing to “sell them in the market”. Most of the girls were later freed.

Rann, in the eastern part of Borno, has been the target of several bloody attacks in recent years.

Two midwives who were abducted from Rann in March were later executed by Boko Haram, despite pleas from the International Committee of the Red Cross, their employer, to show mercy.

Buildings in Rann were burned to the ground during the Boko Haram attack. Photograph: Silas Adamou/MSF

“I’m deeply sadden by the brutality of the latest violence in Rann, Baga and other parts of Lake Chad,” the ICRC’s Mamadou Sow said on Thursday. “To see tens of thousands of already displaced families fleeing again aimlessly for safety in four different countries is devastating. Enough is enough; people are tired and must be protected.”

Andrew Mews, MSF’s country director in Nigeria, said the attacks gave the lie to suggestions of improved stability in the country’s north-east.

“The emergency is not over yet,” said Mews. “There’s been quite a lot of talk that perhaps the situation is stabilised, and that we could start looking at doing more development activities in the north-east, but the reality is the context doesn’t allow that. We wish that was the case.”

He said that both the international organisations and the Nigerian authorities needed to stay and ensure a “proper humanitarian response” was delivered.

MSF medical teams are focusing on providing emergency support to the 8,000 people who fled Rann. Photograph: MSF

There has been a pattern of increased attacks in Borno state, the epicentre of the Boko Haram crisis, in recent months, with militants briefly taking over the town of Baga and storming a military base, killing many soldiers and looting weapons. They belonged to the other major Boko Haram faction, Islamic State West Africa Province, which broke off from Shekau’s camp in 2016.

The Maiduguri offices of one of Nigeria’s leading newspapers was raided and its bureau chief arrested after it published what the army said was sensitive information about a planned operation to retake Baga.