Strains of Ebola and four other deadly viruses have been imported to Japan for the development of diagnostic kits ahead of an expected influx of visitors for the 2020 Olympics and Paralympics in Tokyo, a governmental research institute said Friday.

The viruses were taken to a branch facility of the National Institute of Infectious Diseases in western Tokyo's Musashimurayama on Wednesday and Thursday, according to an institute official.

The government obtained Ebola, Lassa, South American, Crimean-Congo and Marburg viruses from two foreign research facilities.

The five viruses did not previously exist in Japan and are classified as the most dangerous agents under the country's infectious diseases law. Some African nations are currently in the grip of an Ebola outbreak.

The institute first said last November that it intended to import the five viruses. The decision was finalized in July after discussions with residents near the facility.

The Ebola virus is transmitted through direct contact with bodily fluids of infected people. The four other viruses can also be contracted through contact with infected animals and mites.