Fire crews from NSW and Queensland were called to the main street of Mungindi just before 8pm on Tuesday night to find the buildings well alight.

The town's only supermarket, Spar Supermarket, was destroyed in the blaze, along with their butcher shop, Red's Quality Meats, and clothing store, PJ's Country Wares, as well as a residential flat within the building.

The fire is estimated to have caused $1 million worth of damage, including loss of stock.

"To say that our little community has been through hell and back is an understatement," Mungindi Progress Association president Anna Harrison said in a statement.

"This has absolutely gutted our community.

"After battling the drought, then the borders closing and now losing our essential shops, we are in pain."

Crews from NSW RFS and Fire and Rescue NSW attended the scene, along with Queensland Fire and Emergency, Queensland and NSW police and paramedics.

NSW RFS said no-one was injured in the blaze, which is believed to have started inside the butcher shop.

"At this stage the cause of the fire is unknown," a NSW RFS spokesperson said.

"Fire investigators are on scene determining the cause of the fire, but it could be sometime before that is known."

Officers attached to New England Police District have established a crime scene and an investigation into the cause of the fire is underway.

As part of ongoing inquiries, detectives are urging anyone with information about the incident to contact police via Crime Stoppers on 1800 333 000 or https://nsw.crimestoppers.com.au.

The NSW RFS spokesperson paid tribute to the Mungindi community, which rallied together to extinguish the flames and salvage stock and goods from a number of businesses in the line of fire.

"The local community played a huge part," the spokesperson said.

"Given the remoteness of the town, the community helped in assisting local firefighters until more assistance arrived."

Meanwhile, Northern Tablelands MP Adam Marshall has announced the state government will provide $100,000 in emergency funding to establish a temporary store for the town to ensure locals, who live 120km away from their nearest grocery store, have access to basic essentials.

"Today, I am deeply saddened for the community of Mungindi, which is waking up to the loss of its much loved supermarket, butcher and dress shop, following a devastating fire overnight," Mr Marshall said on Wednesday.

"The destruction of these important businesses in the main street is just another kick in the guts for the affected business owners and community at large, who are recovering from years of drought and have been significantly impacted by the Queensland border closure.

"The coming days and months will be tough, but I give the commitment I will work with the people of Mungindi, and the Moree Plain Shire Council, to ensure everyone is supported in the recovery.

"If there is a community that can rally together and rebuild, I have no doubt it is Mungindi."

Moree mayor Katrina Humphries said "there isn't much left" of the shops and businesses on the NSW side of the Mungindi main street after Tuesday night's fire.

"This is so sad, what else can our beautiful communities have to deal with?" she questioned.

"Our thoughts and love are with the Mungindi community after the horrifying events of last night, we will get through this, the mighty Mungindi community will show us their strength and spirit, once again.

"I am in awe of the community resilience and bravery displayed by so many members of the Mungindi community in the face of such danger and devastation. I have no doubt that the efforts of these individuals prevented more widespread destruction and I am so thankful that everyone stayed safe.

"To the owners of the businesses directly affected by this event we have your back and that you have our unwavering support. After some very tough years, last night's events are truly brutal.

"To the Mungindi community; with some of the affected businesses being the main suppliers of food and goods, we are already working with our own staff and with other levels of government to ensure continued supply of these items to you over the coming days and months.

"The residents of Mungindi have again proved themselves with immense dedication and community spirit. Mungindi is a small town but has a huge heart.

"We know that the road ahead after last night's events will be tough, and we are committed to being part of the recovery every step of the way."

Ms Harrison said although the town is devastated, its community spirit has shone through.

"As you looked around tonight, you saw community spirit at its best," she said.

"People supporting people.

"To our firefighters, ambulance, police Queensland and NSW and MPSC staff thank you for your expertise and action.

"To all the farmers and locals that supplied water trucks and muscle, thank you.

"Thank you to Adam Marshall, Katrina Humphries, Lester Rodgers and Susannah Pearse who took no time to ring and offer support.

"We have an amazing town and we will not be beaten!"