A stream of lava from Hawaii's Kilauea volcano threatens to block a key Hawaii highway that serves as an escape route for coastal residents as two of 22 fissures had merged.
Aerial footage from the U.S. Geological Survey shot on Saturday showed a wide flow of fast-moving lava advancing to the southeast at rates of over 270 meters per hour. The flow was nearly 2.4 kilometers from the ocean, scientists said.
The footage also showed lava fountaining about 100 meters high at one of the fissures.
As magma destroyed four more homes, it was expected to hit Highway 137 overnight if it kept up its rate and direction of flow, according to the County of Hawaii's Civil Defense Agency said.
Authorities are trying to open up a road that was blocked by lava in 2014 to serve as an alternative escape route should Highway 137 or another exit route, Highway 130, be blocked.
The Hawaii National Guard has warned of mandatory evacuations if more roads were blocked.
Two neighborhoods with nearly 2,000 people were forced to evacuate as lava claimed 40 structures.
Since the first fissure opened on May 3, lava had been mostly spattering up and collecting at the edges of the cracks in the ground. However, fresher magma is now coming up and flowing faster and farther.
Kilauea is the most active volcano in the world and one of five on the Big Island. It began erupting on May 3, forcing some 2,000 people to evacuate as lava claimed 40 homes.
Scientists do not anticipate fatalities in the event of a large eruption since most of the exposed residential communities have already been evacuated and the southeastern part of the island where the volcano is located is sparsely populated.
Most of the Big Island and the rest of the state's island chain has not been affected by the volcanic activity. Officials say flights to and from the Big Island and the rest of the state have not been impacted.
County officials, however, have been urging area residents to be ready for possible evacuation, as scientists believe the volcanic activity may precede a major eruption similar to one that rocked the island in the mid-1920s.