TOKYO — Japan’s government on Saturday approved bringing the country’s first nuclear reactors back online since last year’s earthquake and tsunami led to a nationwide shutdown, going against wider public opinion that is opposed to nuclear power after Fukushima.

The decision paves the way for a power company in western Japan to immediately begin work to restart two reactors in Ohi town, a process that is expected to take several weeks.

Despite lingering safety concerns, the restart could speed the resumption of operations at more reactors across the country. All Japan’s 50 nuclear reactors are offline for maintenance or safety checks.

Public opposition to the resumption of nuclear operations remains high because of the crisis the tsunami touched off at Fukushima Dai-ichi plant, the worst atomic disaster since Chernobyl. As the government announced its decision, a protest was held outside the prime minister’s offices.

The restart is being closely watched as an indicator of how aggressively the government will act to approve operations at other reactors. It has been pushing hard to bring some reactors online as soon as possible to avert power shortages as demand increases during the summer months.

It says the reactors in the town of Ohi are particularly important because they are in an area that relied heavily on nuclear before the crisis, and have passed safety checks.

“Safety is our main concern,” said trade and industry minister Yukio Edano. “We have approved the beginning of the restarting process. It will take some time for the reactors to begin generating electricity.”

He said the government would request people continue to save energy, and added that if there are safety problems, the process could be delayed.

Prime Minister Yoshihiko Noda announced the government’s approval after Ohi’s mayor and the local governor publicly stated they support the plan. Local approval isn’t needed legally.

“I approve the plan because I have been assured of the government’s safety efforts and because it will provide stability for our industries,” Issei Nishikawa, the governor of Fukui prefecture which oversees Ohi, said after meeting Noda in Tokyo on Saturday.