A Japanese court on Thursday acquitted three former officials from the firm that operated the Fukushima nuclear plant, in the only criminal trial to stem from the 2011 disaster.
The three former executives from Tokyo Electric Power Company (TEPCO) had faced up to five years in prison if convicted of professional negligence resulting in death and injury.
The court is expected to explain its reasoning for the ruling shortly. In the wake of the verdict, dozens of protesters including some from the Fukushima region, who had gathered before the session began, expressed shock.
"I cannot accept this," one woman said into a microphone, addressing the rally.
The three men are the only people to face criminal prosecution over the worst nuclear accident since Chernobyl.
The meltdown at the Fukushima Daiichi plant was triggered by a tsunami that washed into the facility after a 9.0-magnitude undersea earthquake on March 11, 2011.
No one is officially recorded as having been killed by the Fukushima meltdown, though the tsunami that triggered it left nearly 18,500 people dead or missing.
The men faced prosecution in relation to the deaths of more than 40 hospitalised patients who died after having to be evacuated following the nuclear disaster.
Prosecutors had twice declined to proceed with the case against the executives, citing a lack of evidence and a slim chance of conviction.
But a review panel composed of ordinary citizens ruled in 2015 that the former officials should face trial, forcing prosecutors to proceed.
Prosecutors argued that the three men -- former TEPCO chairman Tsunehisa Katsumata, 79, and former vice presidents Sakae Muto, 69, and Ichiro Takekuro, 73 -- knew the risks to the plant posed by a tsunami in the area.
They accused the men of negligence for failing to take better safety measures.
Lawyers for the defendants argued that the information available to them before the disaster was not reliable, and that they thought officials in the firm responsible for nuclear safety had taken appropriate measures.