Volcano raises new island off the coast of Japan

Remarkable pictures show the new islet, which is about 200 metres (660 feet) in diameter, appearing in the water

Smoke from an erupting undersea volcano forms a new island off the coast of Nishinoshima (AP)

A volcanic eruption has formed a new island off the coast of Japan around 620 miles south of Tokyo.

Remarkable pictures show the new islet, which is about 200 metres (660 feet) in diameter, appearing in the water next to a small, uninhabited island chain known as Nishinoshima.

The 30-odd islands are 620 miles south of Tokyo and along with the rest of Japan are part of the seismically-active Pacific "Ring of Fire".

Television pictures showed the creation of the island amid heavy smoke, ash and rocks exploding from the crater, and steam billowing into the sky.

The area regularly experiences earthquakes and eruptions but rarely as powerful as this one. The forming of the new island is the first such phenomenon for around 30 years.

Japan's chief government spokesman welcomed the news of yet another bit, however tiny, of new territory.

"This has happened before and in some cases the islands disappeared," Yoshihide Suga said when asked if the government was planning on naming the new island. "If it becomes a full-fledged island, we would be happy to have more territory."

The Japanese archipelago has thousands of islands. In some cases, they help anchor claims to wide expanses of ocean overlying potentially lucrative energy and mineral resources.

Japan has plans to build port facilities and transplant fast-growing coral fragments onto Okinotorishima, two rocky outcroppings even further south of Tokyo, to boost its claim in a territorial dispute with China.

Additional reporting by Associated Press