By Junko Fujita
TOKYO (Reuters) - Winds over an earthquake-stricken nuclear power plant in Japan are blowing slowly in a southwesterly direction that includes Tokyo but will shift westerly later on Tuesday, a weather official said.
The wind is moving at a speed of about two to three meters (7 to 10 ft) per second, said the official with the Japan Meteorological Agency who is based in Fukushima Prefecture, the location of three troubled nuclear reactors.
Earlier, Japan's prime minister warned that radioactive levels had become high around the nuclear power plant after explosions at two reactors, adding that the risk of more radioactive leakage was rising.
The Japan Meteorological Agency official said wind speeds will increase on Wednesday, blowing south at three to five meters (10 to 16 ft) per second before changing later in the day to blow easterly out to the Pacific Ocean at a faster rate of five to 12 meters (16 to 39 ft) per second.
There have been a total of four explosions at the plant since it was damaged in last Friday's massive earthquake and tsunami.
The fear at the Fukushima plant is of a major radiation leak after the quake and tsunami knocked out cooling systems.
Jiji news agency said the first explosion on Tuesday damaged the roof and steam was rising from the complex. It also reported some workers had been told to leave the plant, a development one expert had warned beforehand could signal a worsening stage for the crisis.
The worst nuclear accident since the Chernobyl disaster in Ukraine in 1986 has drawn criticism that authorities were ill-prepared and revived debate in many countries about the safety of atomic power.
(Reporting by Junko Fujita. Editing by Jason Szep)