More Saudi army troops may have been sent to quell unrest in the Gulf island state Bahrain 2507111

Security forces from Saudi Arabia and the United Arab Emirates were sent into Bahrain in mid-March to help clear the streets of protesters who had been staging demonstrations since February.

The troops were part of a Peninsula Shield force set up by Gulf Arab states for their mutual defense.

In March 2011, hundreds of troops from Saudi Arabia and police officers from the nearby United Arab Emirates have entered Bahrain at the request of the ruling family, a move that further polarized the tiny island nation and marks the first time Arab nations have intervened in another country's affairs amid sweeping unrest in the region.