Nineteen state conservation officers with support from Hawaii County police Monday dismantled a tent erected near the Mauna Kea Visitors Center, enforcing a rule aimed at stopping protesters from camping.

In an understanding reached last week, protesters had agreed to vacate the tent, so authorities descended on an empty campsite during early morning drizzle at 12:45 a.m.

The operation was the third conducted under a 120-day emergency rule approved in June by the state Board of Land and Natural Resources prohibiting camping in the restricted area between 10 p.m. and 4 a.m. Written notification was posted Wednesday that the tent would be confiscated if it wasn’t taken down.

Video from the state shows officers dismantling the large tent. Officers left untouched a wood-and-straw meetinghouse that protesters erected for prayers and ceremonies.

Protest leaders said they reached an agreement with the state last week to stop sleeping on the mountain as long as officials warn them when the nonprofit company building the Thirty Meter Telescope resumes construction. Protesters had been keeping around-the-clock watch on the mountain to prevent crews from accessing the construction site. Protesters say they don’t want another telescope on a mountain many Native Hawaiians consider sacred.

During two attempts to resume construction, crews were unable to reach the telescope site because of protesters blocking their path. Construction has been stalled since April, and telescope officials haven’t determined when construction will resume.

Because of the agreement, protesters question why the state felt it necessary to conduct Monday’s sweep.

“We already moved out,” said Lanakila Mangauil, a protest leader. “The sense that they need so much force at an odd hour seems like wasted resources.”

Department of Land and Natural Resources spokesman Dan Dennison declined to respond to Mangauil’s comments.

Mangauil said he wants supporters to know they haven’t given up and will be on the mountain regularly during the daytime.

“We weren’t pushed off the mountain,” he said. “We were able to come to an understanding with the state that would secure the mountain.”

Some, however, aren’t comfortable with trusting the state to warn protesters about attempts to resume construction, Mangauil said.

“If that trust is broken, we’ll have to return to the mountain,” he said.

Since July, 15 people have been arrested under the emergency rule. On July 31 six people received citations and seven people were arrested. On Sept. 9 eight people were arrested for allegedly being in the restricted area.