TOKYO (AP) _ Two strong earthquakes rocked a chain of volcanic islands off Tokyo on Friday, sending rocks falling onto cars. An earlier earthquake shoot Tokyo as well.

There were no immediate reports of injuries from the quakes shaking the volcanic islands, but the rocks damaged two cars on Kozushima, about 105 miles south of Tokyo, said Yoshiyuki Umeda, a local official.

On Niijima, several mudslides were reported on roads and in mountain areas, said Ryuji Okada, another island official.

The 10:52 a.m. quake, with a magnitude of 6.0, was centered about six miles under the ocean floor off the islands of Miyake and Shikine in the Izu chain, the Meteorological Agency said.

A second quake with a magnitude of 4.9 hit the same area two hours later.

One of the world's most seismically active countries, Japan has been jolted by a series of earthquakes and the eruptions of three different volcanoes in recent months.

Earlier Friday, an earthquake with a preliminary magnitude of 4.0 jolted Tokyo. A 62-year-old woman broke her shoulder in a fall, said Tokyo Fire Department spokesman Keita Kaneko.

The 4:53 a.m. temblor was centered about 25 miles below the ground. The Meteorological Agency said the quake was not related to the series of quakes shaking the Izu islands in recent months.

Mount Oyama on Miyake, one of the islands, erupted last week for the fourth time in a little more than a month, forcing 634 of the island's 4,000 residents to temporarily seek refuge in community shelters.

Since late June, Miyake and other nearby islands have been jolted by tens of thousands of earthquakes. On July 1, a man was killed by a landslide following an earthquake on Kozushima.

Earthquakes of magnitude 5 are considered very strong, and those of 6 or higher can cause severe damage near their epicenter.