Alexandria, Virginia (CNN) A federal judge Tuesday denied Chelsea Manning's effort to avoid testifying before a grand jury in Virginia.

Speaking outside a courthouse, Manning said the judge, in a sealed hearing, had rejected her effort to quash a subpoena from prosecutors that compelled her testimony.

"The motion to quash, it was denied. We still have grounds to litigate so we're going to be here tomorrow," Manning said.

Manning said it was not clear if she would have to testify before the grand jury on Wednesday, or if that testimony would be delayed as her lawyers continue to fight the subpoena in court.

It is not publicly known what the grand jury in Virginia is investigating and what prosecutors' interest in Manning is. Earlier this year, a judge in the same court declined a group's motion to unseal charges against WikiLeaks founder Julian Assange.

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