TOKYO, Aug. 22 (Xinhua) -- Despite public concerns and raging opposition from both home and abroad, the Japanese government said Tuesday it has decided to start releasing nuclear-contaminated wastewater from the crippled Fukushima Daiichi Nuclear Power Plant into the ocean on Thursday.

Despite pouring rain, hundreds of Japanese gathered on Tuesday morning in front of the Japanese prime minister's official residence to protest the government's irresponsible decision.

The ocean discharge which could last several decades is expected to commence Thursday, weather and sea conditions permitting, according to the controversial decision announced by Prime Minister Fumio Kishida following a ministerial meeting held on Tuesday morning.

Kishida claimed that the government will take full responsibility for the decision.

Following the announcement, the Tokyo Electric Power Company (TEPCO), the plant's operator, said it began transferring the first batch of treated water from storage tanks into a facility to mix it with seawater to dilute it shortly after 10:30 a.m. local time on Tuesday.

"No matter how the wastewater is 'treated,' its nuclear-contaminated nature remains unchanged. All the Japanese government wants is to create a fait accompli with the ocean discharge," said Hideki Taki, one of the rally's organizers, who expressed extreme anger at the government's unilateral move to push forward with the discharge.

He emphasized that those against the discharge are determined to continue voicing their strong opposition and fighting with all their might.

For Yoshiko Furukawa, who used to live near the Fukushima Daiichi nuclear power plant and had been forced into long-term evacuation due to the nuclear accident, the prime minister's claim to take responsibility rang hollow to her. "He lacks the qualifications, authority, and right to assume such responsibility," she told Xinhua at the gathering.

"Nothing will change in our opposition to the release of water into the ocean without the understanding of fishermen and the public," said Masanobu Sakamoto, head of the National Federation of Fisheries Cooperative Associations, in a statement on Tuesday.

Prior to Tuesday's announcement, Kishida visited the wastewater treatment facility at the Fukushima plant on Sunday and met with the head of Japan's national fisheries federation on Monday in hopes of gaining an understanding.

"Our position has not changed, and we continue to be opposed to the ocean discharge," Masanobu Sakamoto, head of the National Federation of Fisheries Cooperative Associations said after the meeting.

Hit by a magnitude-9.0 earthquake and an ensuing tsunami on March 11, 2011, the plant suffered core meltdowns that released radiation, resulting in a level-7 nuclear accident, the highest on the International Nuclear and Radiological Event Scale.

The plant has been generating a massive amount of water tainted with radioactive substances from cooling down the nuclear fuel in the reactor buildings, which are now being stored in about 1,000 storage tanks.

The Fukushima plant has stored more than 1.3 million tons of nuclear-contaminated wastewater, and the discharge is planned to continue for more than 30 years, according to TEPCO.

In 2015, the Japanese government and TEPCO made an agreement with fisheries cooperative associations of both Fukushima prefecture and the nation that they would not proceed with any wastewater disposal "without the understanding of relevant parties."

"I had a faint hope that they would keep the promise, but eventually that was a lie," a 62-year-old fisherman from Iwaki City in Fukushima Prefecture was quoted by local media as saying.

Mizuho Fukushima, head of the Social Democratic Party, criticized the government for disregarding agreements made with stakeholders, arguing that the decision to proceed with the ocean discharge despite widespread opposition amounted to a "reckless act" by the government, trampling over the concerns of the majority.

The legitimacy and safety of Japan's ocean discharge plan have long been questioned by the international community, and residents in Fukushima have pointed out many times that since the nuclear plant accident, TEPCO's handling of the aftermath has been highly problematic.

Earlier this month, leaks were found in a hose used to transfer treated nuclear-contaminated water at the crippled plant after higher-than-usual levels of radioactive material were detected in rainwater in the dike around a storage tank, which has again heightened international concerns over TEPCO's competence.

A total of 88.1 percent surveyed expressed concerns over the government's plan to discharge treated radioactive wastewater into the ocean, as the disapproval rate of the Kishida-led cabinet rose to an eight-month high, according to the latest opinion poll conducted by the national news agency Kyodo.

A Chinese Foreign Ministry spokesman said on Tuesday that China strongly urges Japan to cancel the plan to release nuclear-contaminated water into the sea and dispose of it responsibly.

"This is extremely selfish and irresponsible, as the discharge will spread the risks of nuclear contamination to the rest of the world, and by doing so, Japan is putting its selfish interests above the long-term wellbeing of the entire humanity," spokesman Wang Wenbin told a news briefing in Beijing.

"China is gravely concerned and strongly opposed to this. We have made serious demarches to Japan," he said.

Meanwhile, China's Hong Kong Special Administrative Region and the Macao Special Administrative Region said they would ban certain aquatic products from Japan starting Thursday following Tokyo's announcement of nuclear-contaminated water discharge.

The ban will apply to aquatic imports from 10 Japanese metropolis or prefectures including Tokyo, Fukushima, Chiba, Tochigi, Ibaraki, Gunma, Miyagi, Niigata, Nagano and Saitama, covering all fresh, frozen, chilled, dried or processed seafood, as well as sea salt and seaweed.

In South Korea, activists and politicians condemned Japan's decision to start the nuclear-contaminated wastewater dumping plan.

A group of green activists gathered on Tuesday near the Japanese embassy in Seoul, shouting slogans of "Dead against Japan's maritime release of nuclear-contaminated wastewater," and "Immediately retract the maritime discharge decision."

The Democratic Party said in a statement that each country sharing the Pacific Ocean will have to bear the brunt of unexpected damages from the discharge, stressing that Japan became a damage-causing country by waging invasion wars in the past and releasing radioactive wastewater now.

The South Korean party said the Japanese government chose the nuclear-contaminated wastewater discharge to "save costs," adding that Japan should take the entire responsibility for all situations coming from the release. ■