A strong earthquake has struck off the coast of northeastern Japan, but no tsunami is expected.

The U.S. Geological Survey says the magnitude-6.1 earthquake hit early Thursday and was centered about 107 kilometers northeast of Hachinohe at a depth of 40 kilometers.

Kyodo News agency says the quake shook Aomori Prefecture and other areas of northeastern Japan but no abnormalities were reported at nearby nuclear power plants. No tsunami warning was issued.

A 5.6 magnitude earthquake shook Bulgaria's capital Sofia early on Tuesday, causing residents to rush into the streets, the civil defence office said.

The quake, which occurred at 3 a.m. local time, shook apartment buildings and rattled windows but caused no casualties or damage, Nikolay Nikolov, an official from the office was quoted as saying by the national radio, citing initial reports.

The U.S. Geological Survey said the temblor was cantered about 14 miles (24 km) west of Sofia and occurred at a relatively shallow depth of 5.8 miles (9.4 km).

A small earthquake with a magnitude of 2.3 on the Richter scale hit the western province of Kanchanaburi on Monday, the Meteorological Department's Seismological Bureau reported.

The earthquake struck at 11.51am in Sai Yok district.

There were no reports of damage or casualties.

Japan was hit by two shallow earthquakes in the space of just eight minutes on Sunday, one of them measuring a strong 6.2-magnitude, but there were no reports of damage and no tsunami alert.

The 6.2-magnitude quake struck at 4:20pm (0720 GMT) off Japan’s northeast Pacific coast, the national meteorological agency said, followed by a tremor with a reading of 5.7 at 4:28pm.

The US Geological Survey estimated the magnitude of the first quake at 6.0. The depth of both quakes was about 10 kms, the agency said.

A strong earthquake in northern Italy killed at least six people, injured dozens and damaged historic buildings including a famed mediaeval castle early on Sunday, waking terrified citizens and sending thousands running into the streets.

The quake, which the U.S. Geological Survey recorded at magnitude 6.0, struck at 4:04 a.m. (0204 GMT) and was followed by a series of jolting aftershocks. At least two of them reached magnitude 5.1, sowing fresh panic, further damaging already weakened buildings and causing more structures to collapse.

An earth tremor was experienced by people in Badulla and Nuwara Eliya districts during early hours yesterday.

Geologist H.D.N. Sanjeewa of the Geological Surveys and Mines Bureau (GMSB) said the tremor had been felt by people in Bandarawela, Badulla, Kandy, Minipe, Wattegama, Maturata, Padiyapelalla, Rikillagaskada, Hanguranketha and Welimada areas around 1.45 am yesterday, but there had been no damage.