A woman wearing a face mask walks past an anti-plague institute in Irkutsk, where a female employee reportedly died of suspected plague. (AFP pic)

SHELEKHOV: When a woman died of suspected plague in Siberia last week, Oksana was in the maternity ward for observation.

"Everything was fine, and then they told us that a woman had died. And they wouldn't let anyone in or out," the 35-year-old told AFP.

For four days, she was kept in hospital in Shelekhov, the same town where a 28-year-old lab worker, Darya Shipilova, had been hospitalised before she was reported to have died of plague.

Russian authorities have downplayed the incident, saying that she died from "pneumonia of an unknown aetiology" and that post-mortem analysis showed no trace of an infection connected with her "professional work" at the Irkutsk anti-plague institute.