The Fukushima Daiichi plant, operated by Tokyo Electric Power Co (TEPCO), is located about 240 km (150 miles) north of Tokyo on the country's northeast coast.

The direction of the wind is a key factor in judging possible damage to the environment from the radiation leaking from the plant, which was devastated on Friday by Japan's biggest earthquake on record.

Earlier in the day, the wind was blowing from the south, raising concerns radioactivity could affect residential areas.

"The wind is expected to blow westerly during the night, in the direction where there are no residents," the official said.

The wind speed will be around 2 to 3 meters per second, he said.

The plant was damaged by Friday's 8.9 magnitude quake, which sent a 10-meter (33-foot) tsunami ripping through towns and cities across the northeast coast.

TEPCO said on Sunday that radiation levels at the Fukushima Daiichi nuclear power plant have risen above the safety limit but said this posed no "immediate threat" to human health. An explosion blew the roof off at the plant's No.1 reactor.


For the first time, the Pakistani military has publicly acknowledged that U.S. drones are targeting militants on Pakistani soil.

In a press briefing for Pakistani reporters Thursday, a military commander said U.S. drone strikes were killing mostly militants and al Qaeda fighters, not civilians.

"Most of the targets are hardcore militants," said Maj. Gen. Ghayur Mehmood. "The number of innocent people being killed is relatively low."

Before Mehmood's statement Pakistani officials had only acknowledged U.S. drone strikes in private while publicly condemning them and calling for them to stop.

Since 2007, 164 drone strikes have killed 964 militants, Mehmood told reporters in the militant stronghold of North Waziristan.

Of those, 171 of the fatalities were al Qaeda fighters from mostly central Asian and Arab countries, he said. Mehmood didn't provide any statistics on civilian casualties and didn't say how the military collected its data on drone strikes, which were considerably lower than tallies kept by CNN and several other independent estimates.

Based on a count by CNN, there have been been 205 U.S. drone strikes since 2008. A recent report by New America Foundation, a U.S.-based think tank, said most of the militants killed by the unmanned aerial strikes were low-level fighters.

Human rights groups inside and outside Pakistan have condemned the drone strikes, saying they've killed hundreds of civilians.

Despite the Pakistani military's claim of a high militant death toll in drone strikes, Mehmood told reporters the attacks have a negative impact on Pakistan's security.

"Definitely, they have social and political repercussions and our law enforcement agencies have to face the fallout," Mehmood said.

U.S. officials rarely acknowledge publicly the CIA's secret drone program in Pakistan. Privately, U.S. officials say the covert strikes are legal and an effective tactic in the fight against extremists.