TOKYO -- Thousands of people have gathered outside the Japanese prime minister's office to protest a nuclear reactor startup set for this weekend.

At least 10,000 protesters filled the street outside Prime Minister Yoshihiko Noda's office Friday, blocking traffic and chanting "No to restart!" as they held up banners with anti-nuclear slogans. The rally was the latest weekly protest held there this month. Noda's government recently approved a resumption of two reactors in western Japan.

One of them, Ohi No. 3 reactor, will be switched on Sunday for the first time since last year's tsunami disaster triggered meltdowns at the Fukushima Dai-ichi plant.

All 50 of Japan's commercial reactors are offline for maintenance or safety checks.

Noda's government has pushed to bring some reactors online to avert power shortages during the summer.