3:45 PM PT -- Rihanna has now tweeted a message praying for peace ... and an end to the conflict in the Middle East.
Rihanna deleted her #FreePalestine tweet 8 minutes after she posted it because she says it was never meant to be sent out in the first place ... a source close to the singer tells TMZ.
One source connected to the situation tells TMZ, "She deleted it because it was never meant to be tweeted," adding, "She didn't even realize it was a tweet until she started hearing from her fans."
The source says Rihanna was reading about the Middle East conflict online when she clicked a link. The next thing she knew ... her fans were asking her why she was pro-Palestine.
Our source says Rihanna is not pro-Palestine or pro-Israel ... "she is pro-peace," saying, "She doesn't want innocent people dying."
So we gotta ask ...