Landslides and damage to roads and other structures have been reported on Kozu Island in the Izu chain following a magnitude 6 earthquake that struck early Sunday morning, police said Monday.

No one was injured by the temblor, which measured lower 6 on the Japanese intensity scale to 7, they added.

Four concrete walls collapsed, police said, while landslides were reported at 21 locations, water pipes were ruptured in three areas and roads caved in at 10 places.

Some landslides were also reported on nearby Niijima and Shikine islands.

Meanwhile, schools on Kozu Island held closing ceremonies Monday as summer vacation starts today, 10 days earlier than usual after the island was rattled by a series of strong earthquakes.

As of Thursday, more than 100 of the 270 students at the island’s elementary school and junior high school, and 27 of the 74 students at its high school had evacuated Kozu Island, which has about 2,300 inhabitants.

Administrators ended classes early to ensure the safety of the students, especially as the elementary school is in an area that is under an evacuation order.

The elementary and junior high schools will begin their second semester Aug. 23, a week earlier than usual.