Hawaii activates National Guard as Mauna Loa lava nears major highway, pockets of natural gas

The continuing flow of lava from the eruption roughly nine days ago from Hawaii's Mauna Loa volcano has now forced the island state to activate its National Guard. 

The state's emergency management said Monday that 20 Hawaii National Guard service members were put on active duty to assist with traffic control and other roles in response to the Nov. 27 eruption.

The Interior Department said lava flow is now just roughly two miles away from a major highway known as Saddle Road.

"There continued to be several small overflows from main channels recorded over the past day," the federal agency said Monday.

Officials previously said the volcano would likely be confined.

Lava advanced Monday at a rate of about 20 feet per hour.

"Though the advance rate has slowed over the past several days, the lava flow remains active with a continuous supply," the federal department also said.

Lava advance rates "may be highly variable" over the next several weeks, according to officials.

Authorities warned that lava may flow into vegetated areas and create secondary fires or even cause methane explosions by igniting underground natural gas pockets.

Residents are urged to take precautions against volcanic glass fragments, which are being blown hundreds of meters away from the eruption.