Japan Lifts Tsunami Warning after 6.5 Quake

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Japan lifted a tsunami warning after a 6.1-magnitude earthquake hit off the northeast coast of Japan on Monday, the weather agency said.

The Japan Meteorological Agency had earlier issued a 50-centimeter tsunami warning for the Pacific coast of Miyagi prefecture, which was devastated by the huge earthquake and tsunami that hit on March 11.

The U.S. Geological Survey had earlier alerted a 6.5-magnitude earthquake but then downgraded its strength. The epicenter was at a depth of 17 kilometers, it added.

Japan's weather agency said that the quake was likely an aftershock of the massive tremor more than two weeks ago, and warned of more to come.

Meanwhile, Japan Monday criticized as "absolutely unacceptable" a radiation reading error by the operator of a crippled atomic plant, where dangerous conditions have disrupted crucial work for two days.

Work has been halted at reactor two of the Fukushima plant that is at the center of Japan's cascading disaster -- an earthquake that sparked a tsunami which in turn triggered the world's worst nuclear emergency since Chernobyl.

Engineers are racing to restore cooling systems knocked out by the tsunami, but fear that radiation has already escaped, either through leaks in the steel-and-concrete reactor casings or their pipe systems.

Embattled operator Tokyo Electric Power Company (TEPCO) doesn't know for sure what happened inside three reactors after explosions ripped away or damaged their outer buildings, designed as the final barrier to the atmosphere.

The company came under fire Monday, a day after it erroneously said radiation in water at the stricken site had reached 10 million times the normal level, later issuing a much lower -- but still dangerous -- figure.

"Considering the fact that the monitoring of radioactivity is a major condition to ensure safety, this kind of mistake is absolutely unacceptable," said top government spokesman Yukio Edano.