US health officials are ‘aware of’ and ‘closely monitoring’ the suspected plague outbreak in Russia as reports emerge of a second death.

A spokesperson for the Centers for Disease Control and Prevention (CDC) told the Daily Mail: ‘CDC is aware of and closely monitoring reports of a suspected case of pneumonic plague in the Irkutsk region of Russia that resulted in a death.

‘We are working across the US government to assess developments as additional information becomes available.’

Agency officials said there was currently ‘no indication… of a broader threat’ to the US, but they were continually monitoring for updates.

Panic broke out last week when Darya Shipilova, 28, a lab worker at the Irkutsk Anti-Plague Research Institute in Siberia reportedly told medical staff that she had accidentally broken a test tube containing live bacteria.

Hundreds of people she came into contact with and five hospitals, including a maternity unit, were placed into quarantine. Shipilova was hospitalized and died from the infection on October 2.

Russian officials claim Shipilova died from an ‘unidentified pnuemonia’, but reports suggest she was infected with pneumonic plague caused by the ‘Black Death’ bacterium, which infamously killed millions in Europe during the Middle Ages.

Countries on the border with Russia, including Mongolia, Kyrgyzstan and Uzbekistan are tightening border health controls over the situation.

Today, claims have emerged that a second person has died of the plague in Russia’s Irkutsk region, which have been attributed to local media.

Russian reports on the first plague case reported in Irkutsk have been disappearing across national media, including one from Moscow’s Channel 5 broadcaster. Independent Russian outlet The Insider said on October 2 the federal television channel REN TV also deleted all five of its publications about the plague in the Irkutsk region.

President Donald Trump has offered Russia help and said that the US government is looking at the outbreak ‘very strongly’.

But the Kremlin declined US help and instead offered to help America with its measles outbreak, which is now the worst in the country since 1991.

Secretary of State Marco Rubio has warned that the disease could ‘quickly spread’, but said that there was no immediate cause for alarm. Speaking before flying to Iceland yesterday, he told reporters there was ‘very little’ travel between the US and Russia and that officials were ‘monitoring’ the situation closely.

In a statement to the Daily Mail, the CDC said: ‘At this time, there is no indication from available reporting of a broader threat to the United States, but CDC and our interagency partners are prepared and will continue to monitor the situation closely.’

The plague is a serious infection caused by the bacterium Yersinia pestis that can cause swollen lymph nodes, particularly at the groin, armpit and neck, coughing up blood and bleeding under the skin.

Read More: CDC is ‘closely monitoring’ possible plague outbreak in Russia as reports emerge of second death