Via the BBC:  Egypt: Mubarak and sons detained amid corruption probe

"The prosecutor general orders the detention of former President Hosni Mubarak and his sons Gamal and Alaa for 15 days pending investigation after the prosecutor general presented them with the current state of its ongoing investigations," said a post on the prosecutor general’s Facebook page on Wednesday.

The piece does not indicate the type of detention.

As a side note:  everyone really is on Facebook these days it seems.