A sleepy block in the Outer Richmond was shaken Tuesday evening, when a gun-wielding mugger discharged his weapon during a robbery.

It was 10 p.m. Tuesday when police say that a 37-year-old man and a 36-year-old woman were "gathering their things from the trunk" at the westernmost end of Clement Street, which is near Seal Rock Drive.

Suddenly, the man and woman were approached from behind by a two men in their late 20s. As one of the men pointed a handgun at them, the miscreants demanded that the victims hand over their property.

Fearing for their lives, the victims gave the men their camera equipment, a tablet computer, a driver's license, a passport, and an undisclosed amount of cash.

Though the victims complied, the gun-wielding man still "fired a shot in the air" as they duo fled in an "unknown direction," police say.

Neither of the victims were injured in the robbery, the San Francisco Police Department confirms. But as of Wednesday morning, the muggers remain on the loose.

Related: Richmond District Muggers Demand Pizza At Gunpoint