A spokesperson for Tokyo Electric Power Co. (TEPCO), operator of the faltering Daiichi facility, said a total of 1,260 tons of water will be discharged over the next seven hours.

An unmanned vehicle with a 22-meter high platform was utilized in the efforts to avoid personnel coming into contact with excessive amounts of radiation.

The Tokyo Fire Department's special "hyper rescue team" also joined the SDF in spraying water to cool down the No. 3 reactor and the combined effort discharged 60 tons of water in 20 minutes, in the first phase of the operation on Saturday morning.

The government has set an exclusion zone covering areas within a 20-km radius of the plant and has urged people within 20 to 30- km to stay indoors.

The Nuclear and Industry Safety Agency raised the severity level of the crisis-hit reactors to 5 from 4 on an international scale Friday, the same level as the Three Mile Island accident in the United States in 1979.

*** On Saturday, an earthquake measuring 5.9 on the Richter scale jolted off the east coast of Honshu, Japan at 10:22 a.m. local time (0122 GMT), the U.S. Geological Survey said.

The epicenter, with a depth of 9.20 km, was initially determined to be at 39.6 degrees north latitude and 143.1 degrees east longitude.