Liquefied natural gas imports by electric companies increased by 15 percent in October as all but two of the nation's reactors remained idled because of safety concerns.

The country's 10 regional power utilities imported almost 4.5 million tons of LNG last month, up from 3.9 million tons a year earlier, according to data released Tuesday by the Federation of Electric Power Companies.

Fuel oil purchases rose 31 percent last month to 1.28 million kiloliters, or about 259,000 barrels, a day, while crude oil purchases rose 18 percent to 1.12 million kiloliters, figures showed. Coal purchases climbed by 5.7 percent to 4.36 million tons.

Thermal power generation increased 7 percent from a year earlier, according to the federation. The average operating rate of nuclear plants in October was 5.2 percent, down from 18.5 percent a year earlier, it said.

All 50 of Japan's functioning nuclear reactors were idled for safety checks after the Fukushima crisis began in March 2011. Two units at Kansai Electric Power Co.'s Oi plant in Fukui Prefecture have been the only reactors allowed to be restarted.