Hacer guardia (un vigilante, un soldado, un policia, un oficial, un funcionario...)

Foto: Diario Notitarde

To stand guard, tu guard something, to keep guard.

Do not worry. The police will stand guard over the door.

In News:

"The Old Guard guarded the tomb every minutw of every day since April 6, 1948. Today will be no exception."
Fox

"Tomb of the Unknown soldiers stand guard during Hurricane Sandy"
Fox

"Spc. Brett Hyde, Tomb Sentinel, 3rd U.S. Infantry Regiment (The Old Guard), keeps guard over the Tomb of the Unknown Soldier."
Fox

"A former Marine and father of two decided to help ease his daughter's fears after the tragic school shooting in Connecticut late last week by standing guard outside her west Nashville school."
News 2 ABC.