Local are claiming the Pakistani army is also involved in the Bahrain suppression. I have heard from friends that 11 AK regiment is stationed there, though I have no idea if they are actively involved (remember, General Zia personally led an armor unit in suppressing the Black September uprising in Jordan in 1970...the Pak army is very conscious of its role as defender of the rulers of the faithful and the monetary rewards this defence brings..incidentally, now that the US and GHQ are not always on the same page, GHQ is likely to be more cooperative with Arab despots, since they anticipate having to scramble for foreign exchange if the US dollar pipeline eventually gets constricted).
And of course, the Sultan has always had battalions of Pakistani mercenaries as added insurance (led, at one point, by an ex-SSG commando colonel, but I have forgotten his name).
Saudi troops seem to be directly involved as well.