FREDERICTON -- A decision by New Brunswick's Progressive Conservative government to allow shale gas development in one region is drawing sharp criticism from Indigenous leaders who say they weren't properly consulted.

Premier Blaine Higgs confirmed on Tuesday that his government has quietly passed regulatory changes to permit the method of extracting hydrocarbons to resume in the Sussex area.

The process known as fracking involves pumping water and chemicals deep underground at high pressure to fracture layers of shale and release pockets of gas.

Higgs's move fulfils a commitment his minority government made in its throne speech earlier this year and is in line with his party's past support of the process.

However, the organization that represents Mi'kmaq chiefs -- Mi'gmawe'l Tplu'taqnn Inc., or MTI -- denounced the step as secretive and a step backwards in the province's relationship with Indigenous populations.

A 2016 final report of a commission on the shale gas issue had urged the province to rebuild its relationship with Indigenous peoples, and to maintain the moratorium introduced in 2014 by the Liberals.

The decision by former Tory Premier David Alward to embrace the shale gas industry led to a series of public protests, culminating in a violent demonstration in the fall of 2013 in Rexton.

A total of 40 people were arrested and six police vehicles were burned. Many of those arrested were Mi'kmaq residents involved in the protests.

Corridor Resources currently has 32 producing wells in the Sussex area and operates a 50-kilometre pipeline, and a natural gas processing facility.

In a corporate presentation, the company has said if the moratorium is lifted, it would drill five vertical evaluation wells, complete three existing wells, identify "sweet spots" and drill a second round of up to five horizontal wells.

Higgs has argued that with dwindling gas supplies off Sable Island, gas prices will increase dramatically if new supplies aren't developed in the Atlantic region.