The World Health Organization (WHO) has requested additional information from Russia regarding the circumstances surrounding the death of a female employee at a plague research institute, according to infohub.kz.

According to Fox News, the WHO is verifying reports of the death of a second laboratory employee in Russia, while the United States is also demanding explanations.

The WHO is conducting an investigation because a laboratory employee in Russia died of severe pneumonia following reports of a possible accidental infection with pneumonic plague.

"Russian health authorities have informed WHO that no cases of plague have been recently registered in the Irkutsk region, and testing of contacts of the deceased did not reveal the presence of dangerous pathogens. Nevertheless, questions remain. WHO is currently requesting additional information on the causes of the employee's illness, on which specific pathogen prompted the sanitary and epidemiological measures, and on reports that a second laboratory employee developed pneumonia of unknown etiology," the publication states.

Recall that earlier media reported that in Russia's Irkutsk region, a female employee of a plague research institute died with suspected plague. It was assumed that the deceased accidentally broke a test tube containing a dangerous bacterium in the laboratory while collecting biomaterial for diagnosis.

The cause of death of the 28-year-old woman in the Irkutsk region is described as pneumonia of undetermined etiology.

Soon after, the Ministry of Health reported on measures taken in Kazakhstan following information about a suspected case of a particularly dangerous infection in Russia.

The World Health Organization (WHO) also assessed the risks associated with the suspected plague case for the Russian Federation and European countries.