Dustings of ash were expected downwind of Kilauea on Thursday, local time, as summit earthquakes set off rockfalls into the lava lake and sent up plumes of steam, ash and smoke, the USGS said.

Local meteorologists said the change in prevailing winds could send Kilauea's volcanic smog, or vog, north-west to Maui and other islands in Hawaii.

Authorities on Thursday completed the removal of highly flammable chemicals from a nearby power plant in the path of lava.

Geologists said Kilauea may be entering a phase of explosive eruptions not seen in nearly a century that could hurl "ballistic blocks" weighing up to 12 tons for 800 metres, shoot pebble-sized projectiles for miles and dust downwind towns with volcanic ash and smog.

The Leilani Estates residential area remains in greatest danger, with 15 volcanic fissures so far having destroyed 36 structures, most of them homes, and forcing the evacuation of about 2000 residents.

In Pahoa, the nearest village to Kilauea, some schools remained closed after the area was hit last week by a 6.9 magnitude earthquake, the biggest since 1975.

Reuters