Several hundred people without face masks caused a disruption at the Tokyo District Court on Tuesday, ahead of a hearing of a case brought by plaintiffs opposed to COVID-19 vaccinations.

Court officials scrambled to implement anti-coronavirus measures after a long line of unmasked people formed at the security checkpoint of the building's entrance ahead of the hearing, which was due to begin at 1:30 p.m., with some other visitors seen complaining they would be late for their sessions.

The plaintiffs have claimed in the lawsuit that "there is no scientific evidence of vaccine safety. The effectiveness of masks is also questionable."

Photo taken April 11, 2019, shows a court sign at the entrance of a building that houses the Tokyo district and high courts in Tokyo's Kasumigaseki area. (Kyodo) ==Kyodo

Using their website, the plaintiffs called on people to come to the court and hear the first oral arguments of the suit. The Tokyo High Court, which manages the building, advises visitors to wear masks but cannot compel them.

The lobby of the building on the first floor and the outside of the courtroom for the hearing on the seventh floor were overcrowded with unmasked people.

According to a nearby police station, the group was believed to number more than 300, and some police officers were sent outside the building.

The plaintiffs are demanding that the government cancel the fast-track approval granted to COVID-19 vaccines earlier this year. They are also opposed to the government's plan to introduce so-called vaccine passports, according to their website.

Over 60 percent of Japan's population has been fully inoculated since the government approved COVID-19 vaccines, including those developed by U.S. pharmaceutical giant Pfizer Inc. and its German partner BioNTech SE.

Japan plans to widely use vaccine passports for commercial purposes as part of efforts to normalize social and economic activities that have long been stagnant due to the coronavirus pandemic.

In recent weeks, Tokyo has seen a sharp fall in COVID-19 cases in tandem with stepped-up vaccinations. But people are still urged by the government to wear face masks to prevent the spread of the virus.

The capital hit a record 5,773 cases on Aug. 13, days after the closing of the Olympics.

People wearing face masks walk in Tokyo's Shibuya area on Sept. 28, 2021. (Kyodo)