Brazil began a 28-day bird flu observation period on Thursday which it hopes will show the country's chicken farms are free of the disease after local authorities said a farm where its first outbreak was detected had been fully disinfected.

The Brazilian government on Thursday said that Russia, Belarus, Armenia and Kyrgyzstan have banned chicken imports from the Brazilian state where the country's first bird flu outbreak occurred on a commercial farm, reported Reuters .

Brazil initiated a 28-day observation period to confirm its chicken farms are bird flu-free after a recent outbreak in Montenegro was reportedly disinfected. Authorities remain vigilant due to the virus's two-week incubation period,