"Don't forget Fukushima" was the message Tuesday morning as roughly 16,000 people gathered in downtown Tokyo to protest the restart of Japan's nuclear power plants.

The demonstration, held outside the official residence of Prime Minister Shinzo Abe, came a day after the government outlined plans to restart two reactors at the Sendai nuclear plant in southern Japan at a five-day meeting of the International Atomic Energy Agency, Jiji News reports.

"Three and a half years have passed since the nuclear accident, but self-examination has yet to be made," Nobel literature laureate Kenzaburo Oe declared at the rally, referencing the 2011 nuclear meltdown at the Fukushima Daiichi nuclear plant.

The Japanese government has been pushing to restart many of the 48 nuclear reactors shut down in the wake of the Fukushima disaster, despite widespread disapproval and concern over inadequate oversight or safety precautions. According to a recent poll, roughly 60 percent of the Japanese population is opposed to the Sendai restart.

The government, Oe said, is "going ahead with the plan to resume operation at the Sendai plant without compiling sufficient anti-disaster plans."

After the rally protesters marched through downtown Tokyo with banners reading, "We don't need nuclear plants," AFP reports.

"Nuclear energy is billed as a cheaper alternative," protester Yoriko Yoshida told CBS News. "But if you factor in the damages that need to be covered after an accident, it isn't cheap at all."

It has been estimated that the Fukushima clean up will cost billions of dollars and take over forty years to complete. The Tokyo Electric Power Company is still struggling to contain radioactive water at the plant, where, according to officials, the "highly contaminated water" continues to flow from the crippled reactors, mix with groundwater and stream into the ocean.