Puerto Varas: Spectacular bursts of volcanic lightning and lava lit up the night sky in southern Chile as the Calbuco volcano erupted twice after half a century of inactivity, forcing some 5,000 people to evacuate.
The surprise eruptions prompted officials to declare a state of emergency, send in the army and evacuate a 21-kilometer (13-mile) radius around the volcano, which last erupted in 1961 and had not shown any signs of increased activity.
There were no immediate reports of injuries, but a 21-year old mountain climber has been reported missing.
The eruptions sowed panic in the nearby port city of Puerto Montt, a tourist gateway to the popular Patagonia region whose mayor said residents were "very, very frightened," amid warnings that melting snow and ice could flood rivers.
The massive ash clouds belched into the sky forced airlines to cancel flights and drifted as far away as southern Argentina -- including the picturesque ski resort of Bariloche, which warned people to stay home to avoid inhaling dust particles.
The first eruption, which started around 6:00 pm (2100 GMT) Wednesday and lasted about 90 minutes, spewed a giant mushroom cloud of ash 10 kilometers into the sky, which turned hues of pink and yellow as the sun set over the area.
Seven hours later, the volcano erupted again, this time shooting lava into the air and generating volcanic lightning, a phenomenon researchers believe is caused by the emission of large amounts of volcanic material charged with static electricity.
Bluish-white bolts of lightning cut through the red and orange plumes of lava in a stunning display of nature's power that played out against the backdrop of the starry night sky.
Chile's National Geology and Mining Service warned a third eruption was likely over the next few hours.
On a 0-8 scale measuring volcano eruption strength, the first one came in at four or five, the interior ministry said.
The second was more powerful still, said the National Geology and Mines Service.
President Michelle Bachelet said she would travel to the affected area Thursday along with several ministers.
"The ash might damage crops, animal feed, bridges, roads, people's work routines, tourism and especially their health," she said.
"We don't know how the situation is going to evolve. It's pretty unpredictable."
Until minutes before the blast, volcano eruption monitoring systems had picked up nothing. In fact, volcano watchers in Chile had been watching another one, Villarica, for a possible eruption.
