A huge earthquake, measuring 6.6 on the Richter scale, shook up Japan Monday at the same time officials expanded the nuclear radiation evacuation zone. Initial reports of a 7.1 quake were later downgraded. Lanslides engulfed cars, and several people were trapped.

The extent of the damage from the new tremors is not yet known. A tsunami warning was posted and then removed. Workers at the damaged Fukushima nuclear plant were temporarily evacuated. Electric power was disrupted but later restored.

Monday’s tremors shook up Tokyo, where a newscaster was rattled by the quake while delivering a news report. At the same time, Japanese citizens attended several ceremonies in memory of the victims of the March 11 disaster.

Last month’s earthquake-tsunami disaster killed at least 25,000 people. Thousands remain buried under rubble, and there is a danger of further radiation from the Fukushima plant, located approximately 140 miles northeast of Tokyo.

China is concerned that contaminated water will reach its coast, and a Japanese official said that contaminated soil has forced the evacuation of thousands more residents for an undetermined amount of time.