MOSCOW, Oct 6 (Reuters) - Russia's health watchdog said on Tuesday that no cases of plague had been detected among people who had come ‌into contact with a Siberian plague institute laboratory worker who died ‌last week.

Authorities say the 28-year-old woman died on Friday from pneumonia of an as-yet unestablished origin, in ​a case that has prompted international concern, including from US President Donald Trump.

Rospotrebnadzor, the watchdog, said in a statement that no infectious diseases had been reported among the staff of the same plague research institute in Irkutsk over the past 10 ‌days and that extensive testing ⁠had found no microorganisms in the deceased woman's body linked to her work.

Elena Sofina, deputy head of the Shelekhov district near Irkutsk, ⁠where a local hospital was placed under quarantine, said that what she called "a dangerous diagnosis" had not bee...