Officials in Hawaii fear lava could enter the ocean following an increase in volcanic activity from the Kilauea Volcano on Saturday.

Large streams of lava have erupted from fissures below Leilani Estates on Hawaii’s Big Island. Aerial images showed numerous fingers of fast-moving lava streams flowing downhill, threatening homes and property in their way.

Local media reported that the lava flow was less than a mile (1.6 kilometers) away from Highway 137 that runs along the southeastern shore of the Big Island, raising concerns that the lava could enter the ocean in a matter of hours.

Scientists expect Kilauea, one of the world’s most active volcanoes, to experience a series of explosive eruptions that could spread ash and volcanic smog across the Big Island, the southernmost of the Hawaiian archipelago. That could pose a hazard to jet engines if it blows into aircraft routes around 30,000 feet (9,144 meters).