Madonna [ tickets ] reportedly called off tentative plans to perform three shows in Israel because terrorists threatened to kill her and her two children if she went forward with the performances.

The U.K. tabloid The Sun reported today that Madonna had initially planned to go ahead with the concerts. She reconsidered after her Los Angeles office received threatening letters--said to be from anonymous Palestinian militants--that contained specific details about her children, Lourdes, 7, and Rocco, 3.

An unnamed source reportedly told the newspaper, "The notes were unbelievably scary. Madonna [ tickets ] is a strong woman but she freaked out when her kids were mentioned."

According to Israeli news reports, Madonna, who last performed in Israel in 1993, planned to play three September shows in Tel Aviv, including a televised Sept. 11 show that was to commemorate the third anniversary of the terrorist attacks on the World Trade Center and Pentagon.

Madonna's Re-Invention world tour is scheduled to open tonight in the Los Angeles area.