He also said that all of the patients’ contacts have reportedly been identified, and none have shown symptoms of illness.
The WHO has pegged the risk at present to Irkutsk as moderate to low, to Russia as a whole as low, and to Europe as very low. The risk assessment will be updated once more information becomes available.
U.S. officials have said they are monitoring the situation.
“There was a worker at the lab that was infected and there’s concern that that [it] could have spread, at least internally,” Secretary of State Marco Rubio told reporters on Monday.
“I don’t think it’s cause for alarm, but it is cause for focus and the cause to just keep an eye on it, and we’re doing that.”
“We’re looking at it very strongly. We just heard about it,” President Donald Trump told reporters separately.
He added that the United States would assist Russia.
“It is always very good when mutual assistance is offered,” Kremlin spokesman Dmitry Peskov said on Monday during a press conference in Moscow.
Peskov encouraged people to look to Rospotrebnadzor’s statements, rather than “rumors” and “speculations.”
Elena Sofina, deputy head of the Shelekhov district near Irkutsk, where a local hospital was placed under quarantine, said that “a dangerous diagnosis” had not been confirmed and that 60 percent of those placed under quarantine as a precaution had already been released.
Reuters contributed to this report.