The Japan Meteorological Agency says earthquake early warnings it issues may be delayed by up to six seconds due to a failure of a seismometer following a massive quake in central Japan on January 1.

The agency says a seismometer in the city of Suzu in Ishikawa Prefecture has stopped working since Tuesday, a day after the quake. Officials say the cause of the failure is unknown.

Suzu City is close to the epicenters for the magnitude 7.6 quake and continuing tremors. Seismic data from there are important for early warnings of earthquakes that take place in the region.

The agency says issuing of early warnings will depend on other seismometers some distance away from Suzu, even when a quake occurs near the city. Officials say it could cause delays in emergency alerts of up to six seconds.

The agency adds that it does not yet know if there have been actual delays in alerts after the failure on Tuesday.

It plans to send officials to Suzu to investigate the cause and repair the seismometer as soon as possible.

The agency says that even though delays in alerts may be expected, people must take immediate action to protect their lives once an alert is issued.