A worker cleans up a floor scattered with CDs and videos at a rental video shop in Tsukuba, north of Tokyo Wednesday, Feb. 16, 2005. (AP Photo/Kyodo News)

An earthquake measuring 5.4 on the Richter scale shook the Tokyo area before dawn, jolting many residents out of bed and causing minor injuries to at least 19 people.

The quake registered at 4:46 am with the epicenter in Ibaraki prefecture about 130 kilometers northeast of Tokyo with a focus 40 kilometers underground, the meteorological agency said.

Part of the Japan Railways Joban line to the northeast of Tokyo and a section of a highway in the Joban region were shut down as precautions as inspectors looked to see if they sustained damage.

At least 19 people were lightly injured when they fell out of bed or were hit by falling objects such as a television and a stereo speaker, according to a roundup of local authorities by public broadcaster NHK.

Police said they had not heard of any life-threatening injuries.

The impact was powerful enough to shake buildings in central Tokyo, waking up many residents, in a reminder of how prone the Japanese capital is to earthquakes.

A government study published in December found it likely that the city of 12.5 million would be hit by a major earthquake within the next 30 years that would leave up to 13,000 dead and disrupt the lives of millions.

Japan, which lies at the crossing of four tectonic plates, endures about 20 percent of the world's powerful earthquakes, frequently jolting Tokyo and other major cities where buildings are made to be tremor resistant.

On October 23, an earthquake measuring 6.8 on the Richter scale and striking only 13 kilometers underground rocked the central Niigata region, killing 40 people.

It was the deadliest quake in Japan since January 17, 1995, when 6,433 people died after a pre-dawn tremor in the western city of Kobe.

The Kobe quake was the most devastating in modern times to hit a city in the developed world. The 10th anniversary last month was marked in the rebuilt city by a UN conference on how to reduce the risks of disasters such as earthquakes or tsunamis of the type that battered the Indian Ocean in December.

In autumn, nearly one million Japanese took part in earthquake preparation drills to mark another anniversary -- that of the 1923 Great Kanto earthquake which devastated the Tokyo region leaving 142,807 people dead or unaccounted for.

(Agencies)