The former military intelligence analyst has been in jail since May 2019 for refusing to testify before a grand jury investigating WikiLeaks. She was scheduled to appear in court in Alexandria, Virginia, this week.
Chelsea Manning's legal team said Wednesday she was recuperating under medical care after a failed suicide attempt.
Alexandria Sheriff Dana Lawhorne said: "There was an incident at approximately 12:11 p.m. today at the Alexandria Adult Detention Center involving inmate Chelsea Manning. It was handled appropriately by our professional staff and Ms. Manning is safe."
She was subsequently taken to a hospital and is now recovering.
The former US military intelligence analyst has been behind bars since May 2019 for refusing to testify before a grand jury investigating whistleblower platform WikiLeaks. Manning is still scheduled to appear in court on Friday in Alexandria, Virginia, where a judge is set to decide whether sanctions against her for that defiance will be upheld.
Andy Stepanian, a spokesman for Manning's legal team, said in a statement Wednesday that Manning "remains unwavering in her refusal to participate in a secret grand jury process that she sees as highly susceptible to abuse."
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Assange and Manning accused of conspiring against the US
The US government has accused WikiLeaks founder Julian Assange of colluding with Manning to leak classified documents related to the wars in Iraq and Afghanistan, including State Department cables and military videos.
Manning was initially sent to prison in 2010 before being court-martialed and convicted of espionage in 2013 and given a 35-year prison term.
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jsi/sms (AFP, AP, dpa)