Friday's volcanic eruption in a southern Japanese island has prompted the diversion of several flights even as evacuation in the region continues. Black clouds of ash and smoke covered the sky while pyroclastic flows of rock and hot gases reached the ocean, prompting authorities to order the evacuation from the islands. 

Japan’s All Nippon Airways said Friday that it will divert some of its flights to Okinawa and Southeast Asia as a precautionary measure after the volcano on the remote southern Japanese island of Kuchinoerabujima in Mount Shindake erupted suddenly on Friday. However, the airline said, according to Reuters, that it didn’t plan to cancel any of its flights. 

Meanwhile, Japan Airlines, the country's second-largest airline, said in a statement Friday that it will not change any of its routes.

The Kuchinoerabujima Island is located 50 miles southwest of the main island of Kyushu, where Kyushu Electric Power's Sendai nuclear plant is located. However, there was no immediate information about whether the eruption affected the reactors. On Wednesday, the plant had cleared the last safety hurdle imposed by the country’s nuclear regulator after the 2011 Fukushima Daiichi disaster.

Of the island's 137 residents, 120 had gathered at a local evacuation facility, Nobuaki Hayashi, a local village chief, told the national broadcaster NHK, according to the Associated Press (AP). However, he added that some of the residents were still unaccounted for.

A 72-year-old man suffered burns after he was caught in the pyroclastic flow, but there were no other reports of injuries from the island, Reuters reported. The alert level in the region, meanwhile, has been raised to the highest level of five by the Japan Meteorological Agency. 

"There was a really loud, 'dong' sound of an explosion, and then black smoke rose, darkening the sky," Hayashi reportedly said, adding: "It smelled of sulfur.

"The skies here are blue, but smoke is still rising to the west."

The Coast Guard ship headed toward the island to evacuate the residents to the closest neighboring island of Yakushima, as the residents' only access to the outside world is by boat. Japan’s Prime Minister Shinzo Abe said that a military helicopter was on its way, Reuters reported

Mount Shindake erupted last summer too, prompting a level three warning, and the area where the pyroclastic flow occurred has been off-limits since then. In September 2014, Mount Ontake in central Japan erupted, killing 63 people.