Quake rocks downtown Tokyo

Japanese schoolchildren regularly practice earthquake survival drills

TOKYO, Japan (CNN) -- A moderate earthquake has hit Japan's southern Ibaraki prefecture northeast of Tokyo, swaying buildings in the capital city.

According to Japan's Meteorological Agency the magnitude 5.2 quake rocked the region at 11:42 a.m. local time Friday.

The epicenter was located about 70 kilometers (42 miles) northeast of Tokyo and was 50 kilometers (30 miles) underground.

No tsunami or tidal wave warnings have been issued.

Immediately after the earthquake, Narita International Airport outside of Tokyo briefly stopped traffic on its runways for damage checks.

EXTRA INFORMATION • Flash animation: Major earthquakes of 20th century  • Timeline: Major earthquakes in last 20 years     MAGNITUDE GUIDE Below is an interactive guide to earthquake magnitude and severity: Magnitude: Less than 3.5 3.5 - 5.4 Under 6.0 6.1 - 6.9 7.0 - 7.9 8 or greater

All air traffic has since resumed.

Two "bullet train" commuter lines servicing areas northeast of Tokyo were also halted for inspection.

A magnitude 5 quake can cause structural damage if it occurs close to the earth's surface.

Japan, which straddles some of the world most active geological fault lines, is regularly hit by small and moderate quakes.

The country is currently playing joint host to the football World Cup finals, but officials say none of the matches have been affected by the latest quake.