Battling to avert an atomic catastrophe, firefighting teams at the Fukushima No. 1 power station sprayed tons of seawater Saturday at its crippled No. 3 reactor in a seven-hour operation aimed at keeping its spent nuclear fuel rods from combusting.

In the evening, the hosing operation was extended until 30 minutes past midnight at the government's request, the Tokyo Fire Department said.

Elsewhere at the plant, engineers raced to connect a power line to the plant in an effort to restart its crippled cooling system.