Five moderately strong earthquakes rocked buildings across a wide swath of Japan's (search) main island on Monday, injuring at least one person.

The first two quakes — measuring magnitude 5.6 and 4.1 — struck within 15 minutes of each other early in the morning in Chiba state (search), to the east of Tokyo, the Meteorological Agency said.

The shaking was strongest in the town of Hikari and Narita city, near Tokyo's international airport, and was also felt in downtown Tokyo.

In the afternoon two more temblors hit in quick succession in the northern prefecture of Niigata (search), spooking residents who last year suffered the country's deadliest temblor in recent years.

The quakes had a magnitude of 5.0 and 4.1, and were centered in Niigata state. Agency official Yasuo Sekita warned of moderate aftershocks over the next few days.

In Kashiwazaki City, near the epicenter, the quakes caused a 34-year-old woman to slip and hurt her leg and damaged nearly a dozen houses, town halls and school buildings.

An hour after the Niigata quakes, a magnitude-4.5 tremor struck in the central prefecture of Gifu, near Mino city.

Last October, a magnitude-6.8 quake in Niigata killed 40 people and injured more than 2,700, making it Japan's deadliest quake in a decade.

A magnitude-5 quake can damage buildings if it is centered in a heavily populated area, while a magnitude-4 quake can shake buildings and cause hanging objects to sway.