 -- Authorities have started to close in on the remaining camp protesters of the Dakota Access Pipeline, after some occupiers had refused to leave despite an evacuation order set by state and federal authorities.

As of late Wednesday, 10 people were arrested outside of the main protest camp, North Dakota Gov. Doug Burgum said during an evening press conference.

The arrests occurred on the road at the main entrance to Oceti Sakowin protest camp, which is situated at the edge of the Standing Rock Sioux Tribe reservation near Cannonball, North Dakota. Those arrested were willingly outside of the barrier put up by protesters to block police from going inside the dwelling area, according to officials.

Police have yet to enter the inside of the camp where between 25 and 50 protesters remain, the governor said, who indicated that anyone voluntarily leaving overnight into Thursday would not face charges. Camp residents had been given until 2 p.m. local time Wednesday to evacuate the site.

Individuals who were arrested on Wednesday were charged with "Obstruction of a Government Function," a class B misdemeanor, Burgum said.

Protesters started about 20 fires on Wednesday, which were characterized as "ceremonial," with many saying they'd rather burn camp structures than have authorities seize and destroy them. Two people in the camp were injured as a result of fires, one person with severe burns who had to be airlifted to Minneapolis.

Police will attempt camp cleanup efforts again at 9 a.m. local time.

Gov. Burgum has set up a travel assistance center that will offer each protester water, snacks, a food voucher, a personal hygiene kit, a health and wellness assessment, hotel lodging for one night, a taxi voucher to the bus terminal, and bus fare for a return trip home. Transportation will be provided from Oceti Sakowin camp to the travel assistance center in Bismarck.

“This free service will provide protesters with support as they prepare for their return home,” Burgum’s office said in a Facebook post on Tuesday night. “All camp residents are encouraged to take advantage of these amenities.”

Last week, Burgum signed an emergency evacuation order for the Oceti Sakowin camp that reaffirmed a Feb. 22 deadline set by the U.S. Army Corps of Engineers. The Standing Rock Sioux Tribe began coordinating a cleanup in late January, but state officials said it wasn't happening fast enough. The governor’s emergency evacuation order cited increasing temperatures and the threat of flooding as the impetus in accelerating the camp’s cleanup.

"Warm temperatures have accelerated snowmelt in the area of the Oceti Sakowin protest camp, and the National Weather Service reports that the Cannonball River should be on the watch for rising water levels and an increased risk of ice jams later this week," the statement from Burgum’s office read.

"Due to these conditions, the governor’s emergency order addresses safety concerns to human life as anyone in the floodplain is at risk for possible injury or death. The order also addresses the need to protect the Missouri River from the waste that will flow into the Cannonball River and Lake Oahe if the camp is not cleared and the cleanup expedited," the statement added.

The Cannonball River is a tributary of the Missouri River.

How it all began

The 1,172-mile pipeline is nearly finished except for a 1.25-mile segment, part of which will run under Lake Oahe, a Missouri River reservoir in North Dakota just upstream of the Standing Rock Sioux Tribe reservation. Construction of this final phase has been the focus of a contentious legal battle and massive protests in recent months.

While the Army Corps says this area is federally owned land, the Standing Rock Sioux Tribe cites an 1851 treaty that it says designates the land for Native American tribes. The tribe, which claims its members were never meaningfully consulted before construction began, sued in July to block the four-state crude oil pipeline. That lawsuit is pending, and the Army Corps and the company behind the pipeline argued in court papers that they followed a standard review process.

The Standing Rock Sioux Tribe has been at the forefront of the fight against the $3.8 billion Dakota Access Pipeline. The protests have drawn thousands of Native Americans, environmental activists and their allies to the Standing Rock Sioux Tribe reservation. The protesters, who call themselves "water protectors," argue that the pipeline will threaten the reservation’s water supply and traverse culturally sacred sites.

Kelcy Warren, CEO of Energy Transfer Partners, the Texas-based developer behind the project, has said that “concerns about the pipeline’s impact on local water supply are unfounded” and “multiple archaeological studies conducted with state historic preservation offices found no sacred items along the route.”

Granting of the easement

In the final days of President Barack Obama’s administration, Jo-Ellen Darcy, the assistant secretary of the Army for Civil Works, announced on Dec. 4 that an easement would not be granted for the pipeline to cross under the large reservoir on the Missouri River.

Darcy said at the time of the decision that the Army Corps would engage in additional review and analysis, including a “robust consideration and discussion of alternative locations for the pipeline crossing the Missouri River.” She also encouraged the Corps to share company documents containing risk analyses and spill models that had not been made available to the tribes during the initial environmental review.

All these steps, Darcy determined, would best be accomplished by the Army Corps’ preparing a full environmental impact statement allowing for public input -- a process that could have taken years. She is no longer in the position after the change in administrations.

The move to deny the easement was hailed by the Standing Rock Sioux Tribe and other pipeline opponents as a major victory. But on his second weekday in office, President Trump signed a memorandum aimed at advancing the Dakota Access Pipeline, as well as one directed at the Keystone XL Pipeline.

Robert Speer, the acting secretary of the Army, on Feb. 7 announced a decision to terminate the notice of intent to perform an environmental impact statement and to notify Congress of the Army’s intent to grant permission for the crossing under Lake Oahe. Speer said the decision was made based on a sufficient amount of available information.

The Standing Rock Sioux Tribe said in a statement at the time that it will “challenge any easement decision” on the grounds that the environmental impact statement was “wrongfully terminated.” The tribe said it will also “demand a fair, accurate and lawful environmental impact statement to identify true risks to its treaty rights, including its water supply and sacred places.”

If the Dakota Access Pipeline is completed and begins operating, the Standing Rock Sioux Tribe said it will “seek to shut the pipeline operations down.”

The Army Corps on Feb. 8 granted an easement to the developer of the Dakota Access Pipeline, allowing it to install the final segment of the pipeline.

“The safety of those located on Corps-managed land is our top priority, in addition to preventing contaminants from entering the waterway,” U.S. Army Corps of Engineers Omaha District Commander Col. John Henderson said in a statement at the time. “We appreciate the proactive efforts of the tribes to help clean the protest site ahead of potential flooding along the river, typical during the runoff season.”

Tribes challenge easement decision

The Cheyenne River Sioux Tribe, which is part of the Great Sioux Nation, joined the Standing Rock Sioux Tribe’s lawsuit against the pipeline, filing a motion at the U.S. District Court for the District of Columbia on Feb. 9 seeking a temporary restraining order “to halt construction and drilling” under and on either side of the land surrounding Lake Oahe.

The tribe argued that the pipeline “will desecrate the waters upon which Cheyenne River Sioux tribal members rely on for their most important religious practices and therefore substantially burden the free exercise of their religion,” according to a court document obtained by ABC News.

The court on Feb. 13 denied that motion seeking a temporary restraining order.

The Cheyenne River Sioux Tribe also filed a separate motion seeking a preliminary injunction directing the Army Corps to withdraw the easement issued to the pipeline company. The tribe alleges that the easement granted is “entirely unlawful," according to court documents.

“The government has granted the easement, and Dakota Access has begun to drill. This court cannot wait until the harm begins to issue equitable relief. When the free exercise of religion is at stake, a threat certain to that right is enough to constitute irreparable harm,” the Cheyenne River Sioux Tribe stated in a court document.

“And in view of the threat to the tribe’s and its members’ constitutional right, this court may not wait until the oil is slithering under the tribe’s sacred waters. The law entitles the tribe to relief as soon as the government acts to threaten their rights," the Cheyenne River Sioux Tribe added in the court document.

A further hearing on the Cheyenne River Sioux Tribe's motion for a preliminary injunction against the pipeline is set for Feb. 27 in Washington, D.C.

In addition, the Standing Rock Sioux Tribe filed a motion on Feb. 14 seeking “expedited summary judgment" on its claims that this easement decision as well as the Army Corps regulatory actions "are arbitrary, capricious and contrary to law."

Construction resumes

After receiving the easement to build the pipeline across the land on both sides of Lake Oahe, Texas-based developer Energy Transfer Partners announced it would resume construction immediately. The Dakota Access pipeline will connect oil production areas in North Dakota to an existing crude oil terminal near Patoka, Illinois.

On Feb. 21, Energy Transfer Partners said in a filing to the U.S. District Court in Washington, D.C., that the company "estimates and targets that the pipeline will be complete and ready to flow oil anywhere between the week of March 6, 2017 and April 1, 2017." The court filing was required as part of the ongoing legal battle that is challenging the construction at the site by Lake Oahe.

ABC News' Connor Burton, David Caplan, Joshua Hoyos, Tom Kutsch, Luis Martinez, Phillip Mena, Bartley Price, Darren Reynolds, Evan Simon and Catherine Thorbecke contributed to this report.