A Nigerian official said Monday their military knows where the girls kidnapped by Boko Haram are located, but added that military force would not be employed to rescue them.

The militant Islamic extremist group abducted more than 200 schoolgirls over a month ago. Until now, their specific whereabouts have remained unclear and the U.S. deployed 80 troops last week in an effort to search for them.

“The good news for the parents of the girls is that we know where they are, but we cannot tell you,” the state news agency quoted Chief of Defence Staff Air Marshal Alex Badeh as saying, according to Reuters. “But where they are held, can we go there with force? We can’t kill our girls in the name of trying to get them back.”

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