Several dozen demonstrators, the last holdouts from a mass protest of the Dakota Access Pipeline, faced off against riot police on Wednesday as they defied a deadline to end their months-long occupation of an encampment on federal land.

Police arrested a handful of protesters who confronted them with taunts late in the day outside the camp entrance, then retreated as tensions mounted in the standoff, about 40 miles south of Bismarck, the state capital. State officials said about 10 arrests were made throughout the day.

President Donald Trump has pushed for the completion of the pipeline since he took office last month, signing an executive order that reversed an Obama administration decision and cleared the way for the $3.8 billion project to proceed.

Protesters, mostly Native Americans and environmental activists, have spent months rallying against plans to route the pipeline beneath a lake near the Standing Rock Sioux reservation, saying it poses a threat to water resources and sacred tribal sites.

Republican Gov. Doug Burgum and the U.S. Army Corps of Engineers had set a 2 p.m. CST (2000 GMT) deadline for protesters to leave the Oceti Sakowin camp, located on Army Corps land in Cannon Ball, North Dakota.

As freezing rain and snow fell, some demonstrators ceremonially burned tents and other structures at the camp in what they said was a tradition before leaving a dwelling place. Others vowed to stay put.

State officials said protesters had set about 20 fires, and that two youngsters — a 7-year-old boy and a 17-year-old girl — were taken to a Bismarck hospital for burns after two explosions occurred.

At least three dozen protesters could be seen gathering near the camp entrance as the deadline passed. About 20 police vehicles waited up the road and a few dozen protesters remained in other parts of the camp, a Reuters witness said.

“I feel as though now is the time to stand our ground,” said Alethea Phillips, 17, a demonstrator from Michigan who has spent three months at the camp.

Chase Iron Eyes, a Standing Rock Sioux member, said the arrest of protesters would not dampen their determination.

“You can’t arrest a movement. You can’t arrest a spiritual revolution,” he said in a video broadcast.

Protesters and law enforcement have clashed multiple times, and hundreds of people have been arrested since demonstrations at the encampment began in August.

The site has become a major focal point for U.S. environmental activism and Native Americans expressing indigenous rights, with some 5,000 to 10,000 protesters inhabiting the camp at the height of the movement in early December.

Most have drifted since away, as tribal leaders called for a voluntary evacuation of the camp during the harsh winter while they challenged pipeline plans in court. Roughly 300 demonstrators had remained until this week.

Law enforcement officials urged people to leave the camp ahead of the deadline, citing hazards posed by spring floods.

State authorities agreed to a request by camp leaders that only Native American cleanup crews be used. One activist, HolyElk Lafferty, said she had asked that cleanup not begin until after the camp was cleared.

“It would raise the alarm and panic and not promote a peaceful process today,” Lafferty said.

Authorities set up a travel assistance center to provide departing protesters with food, water and health check-ups, as well as a voucher for one night’s accommodation at a Bismarck hotel and a bus ticket home.

A judge denied a request earlier this month by two tribes seeking to halt pipeline construction. The pipeline will be complete and ready for oil between March 6 and April 1, according to court documents filed Tuesday.