Sheriff Ed Gonzalez posted on social media that the robbery happened on 5 Uvalde near Wallisville Road in front of a Food Town grocery store.
According to HCSO, the two suspects approached the courier and tried to grab the bag before pepper spraying the guard and knocking him down.
The suspects did retrieve the bag and fled to a waiting white car before driving off.
Investigators described the suspects as black males between 18 and 22 years old.
The guard is expected to be OK, according to officials.
A rash of similar incidents have occurred within the Houston area, with one happening two days prior.
The Houston Police Department is searching for at least four suspects who got into a shootout with a Brinks armored guard at an ATM in southeast Houston.
On Dec. 3, two suspects stole a bag of money from a Guarda truck in front of an H-E-B in Sugar Land.
Police have not said if the incidents could be connected.
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