The Japanese government has urged local authorities, businesses and citizens not to discriminate against evacuees from the area around the crippled Fukushima nuclear plant.
The call came after some evacuation centres demanded radiation-free certificates from people who lived near the plant, and following reports that hotels have turned them away and their children have been bullied.
"I cannot stress enough how regrettable it is that some heartless people have acted like that," said Koichiro Genba, a state minister for national policy, reacting to the instances of discrimination.
"I want industries and central offices and agencies to give instructions to prevent such incidents from occurring."
The top government spokesman, Yukio Edano, said: "As an objective fact, radioactivity is not anything contagious like infectious diseases."
Such discriminatory acts "are obviously overreactions", said Edano, the chief cabinet secretary.
Since the March 11 earthquake and tsunami triggered the world's worst nuclear crisis since Chernobyl, nearly 86,000 people have had to evacuate, with about 30,000 of them relocated outside Fukushima prefecture.
They include residents from inside a 20-kilometre radius around the Fukushima plant.
More than five weeks since the accident, several cases have emerged in which people from Fukushima have faced discrimination.
In one case that surfaced today, the city of Tsukuba, Ibaraki prefecture, has required anyone from Fukushima prefecture to go through radiation checks and submit medical papers before being accepted into shelters.
"It was a measure for the sake of the evacuees because they need to know whether they had been irradiated or not," said a city official, without explaining why submitting papers to the city would help them do so.
Meanwhile, workers at the quake-hit nuclear plant have begun removing highly radioactive water from a reactor turbine building, a key step towards restoring cooling systems, the government said.
The 9.0-magnitude earthquake and tsunami knocked out power systems at the Fukushima Daiichi plant, causing cooling systems to fail and triggering a series of explosions.
To prevent a nuclear catastrophe, crews have pumped thousands of tonnes of seawater and later freshwater into the reactors and pools, creating a massive amount of radioactive run-off, some of which has leaked into the ocean.
About 10,000 tonnes of highly radioactive water will be transferred from the turbine building of reactor No 2 to a treatment facility inside the plant for processing, Japan's Nuclear and Industrial Safety Agency (NISA) said.
NISA spokesman Hidehiko Nishiyama said the operation would allow emergency crews battling to stabilise the plant to "pour more water into the reactor in order to gradually decrease the amount of water dousing".
"We expect to purify and remove salt from water transferred to the waste treatment facility so that it can be poured into the reactor core again."
The move is necessary in order to start work to restore cooling functions at the nuclear plant, where workers have found turbine buildings, trenches and shafts submerged in highly radioactive water.