With less than three months to go before the start of the summer Olympics, already postponed for a year due to the coronavirus, questions still remain over how Tokyo can hold the global event and keep volunteers, athletes, officials and the Japanese public safe from COVID-19.

In two days since its launch, an online campaign called "Stop Tokyo Olympics" has gathered more than 187,000 signatures, nearing its 200,000 goal and underscoring public concerns over holding the massive sporting event in Japan's capital.

Battling a fourth wave of the pandemic and struggling with a sluggish vaccination campaign, the Japanese government is seeking to extend states of emergency in Tokyo and three other areas until the end of May, the economy minister said on Friday.

Opinion polls in Japan have found a majority of the public is opposed to the Games, which are due to open on July 23.

"We strongly call for the prevention of spread of coronavirus and protection of lives and livelihood by using available resources to stop the Olympics," Kenji Utsunomiya, the online petition organizer, wrote on his website. Utsunomiya is a lawyer who has run several times for Tokyo governor.

But, organizers have repeatedly said the Games will go ahead, unveiling detailed Covid-19 protocols for athletes and officials.

Pfizer Inc (PFE.N) and its German partner BioNTech SE said on Thursday they had agreed to donate their vaccine to help inoculate those participating in the Games.