Tokyo (CNN) -- Smoke was spotted at another nuclear plant in northeastern Japan on Wednesday, Tokyo Electric Power Co. said.

The company said smoke was detected in the turbine building of reactor No. 1 at the Fukushima Daini nuclear power plant around 6 p.m. (5 a.m. ET).

Smoke could no longer be seen by around 7 p.m. (6 a.m. ET), a company spokesman told reporters.

The Fukushima Daini nuclear power plant is about 10 kilometers (6 miles) from the Fukushima Daiichi nuclear power plant, where workers have been scrambling to stave off a meltdown since the March 11 earthquake and tsunami knocked out cooling systems there.

Tokyo Electric Power Co. owns both plants.

After the dual disasters, Japanese authorities also detected cooling-system problems at the Fukushima Daini plant, and those living within a 10-kilometer radius (6 miles) of Fukushima Daini were ordered to evacuate as a precaution.

But since then, officials have not expressed any concerns about possible meltdowns there.

Earlier Wednesday, the Japanese Atomic Industrial Forum, a trade group, said cooling functions were recovered and all the plant's four reactors were in cold shutdown.