Hawaiian volcano spews ash up to 3.3km high

A series of summit explosions from Hawaii's Kilauea volcano has spewed ash up to 11,000 feet (3353m) and dusted the grey powdered rock on communities to the southwest, the Hawaiian Volcano Observatory says.

The three explosions, which began around 12.42am local time on Saturday, marked the latest bursts of ash and volcanic smog from Kilauea during the fourth week of what geologists rank as one of its biggest eruption cycles in a century.

Residents downwind of Kilauea were advised by County of Hawaii Civil Defense to avoid exposure to ash, which can cause eye irritation and breathing difficulties, particularly in people with respiratory problems.

About 40km down Kilauea's east flank, lava gushed from six giant cracks, with molten rock from two fissures advancing over another street of homes in the Leilani Estates housing development, the observatory said in a statement.

The number of houses and other structures destroyed by lava flows in the island's lower Puna district leapt to 82 on Friday from a previous count of 50 after fissures reactivated in Leilani Estates this week.

Another lava flow near the rural housing development slowed and was 137m from Pohoiki Road, where there are dozens more homes, the observatory said.

Around 2000 residents of Leilani Estates and nearby Lanipuna Gardens remain under evacuation orders because of lava flows and high levels of toxic sulfur dioxide gas from volcanic vents.

Contingency plans have been made for a possible helicopter evacuation of up to 1000 residents in a coastal area south of the fissures should their last exit route, be blocked by lava or become unsafe due to gaping cracks, County of Hawaii officials said.