Letters containing the powder were sent last week to an Obama for President office in the Los Angeles neighborhood of Palms, to the offices of the Los Angeles Times and to the McCallum Theater in Palm Desert, said Laura Eimiller, an FBI spokeswoman.

The letter to the Times was addressed to two reporters and carried no return address. "Save the Babies" was handwritten on the envelope's front and "Kill All Obama Supporters" was written on the back of the envelope, which contained a granular substance, said Times Security Manager Larry Belkin.

The letter was similar to the ones delivered to the Obama office and the theater, said FBI officials.