An erupting volcano on this remote South Pacific island burst into spectacular life Thursday — shooting steam and toxic gases 9,845 feet into the sky.

Huge columns of dense white steam and muddy ash spewed above Ambae Island to reach the greatest height seen since the Mt. Manaro volcano began erupting Nov. 27.

Thousands of villagers have been evacuated from the path of a possible lahar, or mud flow, that vulcanologists fear could burst over the crater lip if the eruption continues or intensifies, sweeping away the flimsy homes in its path.

A "red zone" has been declared around the volcano and several ships were ready to evacuate islanders if the situation worsens dramatically.

New Zealand vulcanologist Brad Scott, who is on Ambae monitoring the eruption, said "it remains a low-level eruption, but it could go either way — worsen or slowly subside."

The plumes of steam and gases were bursting from a huge vent in the middle of a muddy gray-brown Lake Vui in the crater — which before the eruptions began last month was a picturesque calm aqua blue.

Pilot Charles Nelson of local charter company Flight Club Vila said the lake "is looking like a huge grubby bowl of hot kava," referring to a murky local drink made of the pounded roots of a local pepper plant mixed with water.

Nelson was speaking after flying close to the erupting volcano Thursday morning.

Dead trees ring the edge of the crater, while trees in dense jungle nearby were covered in ash that has been belching from the volcano.

The huge smoke, ash and gas plume cast a shadow over now deserted villages clinging to the volcano's flank.

Some 5,000 villagers — half the island's population — are squatting in townships in low-lying areas of the northwest and southeast corners of the small island, one of more than 80 in the archipelago, which is studded with active and dormant volcanoes.

The islands, with a total population of 200,000 people, are 1,400 miles northeast of Sydney, Australia.

"We're worried, but it's still not increasing its activity and remains on level 2," or yellow alert, local transport operator Simean Tali said.

The ships mean "we should get off [the island] if it goes up," he added.

Two hospitals on the island have been emptied of patients, and teams of doctors and nurses were on call to fly to Ambae from the capital, Port Vila, if a major eruption occurs, the National Disaster Management Office said.

"Maybe nothing is going to happen, but it is better to be ready than not," the Daily Post newspaper quoted Prime Minister Ham Lini as saying.

Ambae, an hour's flight northeast from Port Vila, lies near the islands of Pentecost and Maewo, which could be used to help resettle people displaced by a major eruption.