Lava erupts from a fissure east of the Leilani Estates subdivision during ongoing eruptions of the Kilauea Volcano in Hawaii, U.S., May 13, 2018. Terray Sylvester | Reuters

Lava flowing from giant rips in the earth on the flank of Hawaii's erupting Kilauea volcano threatened highways on Monday, raising the possibility officials may order thousands of more people to evacuate before escape routes are cut off. Lava from a huge new fissure tore through farmland towards a coastal dirt road that is one of the last exit routes for some 2,000 residents in the southeast area of Hawaii's Big Island. More lava-belching cracks are expected to open among homes and countryside some 25 miles (40 km) east of Kilauea's smoking summit, possibly blocking one of the last exit routes, Highway 132.

Fountains of magma spouted "lava bombs" more than 100 feet (30 meters) into the air as the molten rock traveled east-southeast towards the coastal road - Highway 137 - the Hawaiian Volcano Observatory said. Mass evacuations would be triggered if either highway is hit by lava, said Hawaii National Guard spokesman Jeff Hickman. "There's a lot of worst-case scenarios and roads getting blocked is one of them," said Hickman, standing on Highway 137, in the potential path of the lava flow, some two miles (3 km) away.

Eruptions could last weeks

Dozens of homes have been destroyed since eruptions began 10 days ago and officials have ordered the evacuations of nearly 2,000 residents in the lower Puna district of the Big Island, home to around 187,000 people. The American Red Cross said 500 people sought refuge in its shelters on Sunday night because of worsening volcanic activity. Two more fissures opened in the past 24 hours, bringing the total to 19. "It's optimistic to think that this is the last fissure we're going to see," said Hawaiian Volcano Observatory Deputy Scientist-In-Charge Steve Brantley. A similar seismic event in 1955 lasted 88 days, he said.

Evacuees fill out forms before being allowed to return to their Leilani Estates homes to gather belongings on May 6, 2018, near Pahoa, Hawaii. Frederic J. Brown | AFP | Getty Images