madonnaoly230.jpg Madonna fans beware!

The U.S Embassy is warning Americans of a serious threat being made by an unknown source to harm spectators and performers during the Material Girl's scheduled concert in Russia tomorrow.

Apparently the U.S Consulate General in St. Petersburg received a tip that there was significant cause for concern, and they are warning all citizens who attend the concert to "remain vigilant regarding their personal security."

The threats come days after Madonna voiced her support of jailed Russian punk band P***y Riot, which authorities believe could have contributed to the terror threats.

The concert is still scheduled to happen as planned. Nothing stops Madge from putting on a show!