London (CNN) -- Two works by British artist Damien Hirst worth $54,000 have been stolen from a London gallery.
The pieces -- prints of colored spots, signed by Hirst -- were taken from the Exhibitionist Gallery in Notting Hill in the early hours of Monday morning.
Detective Sergeant Jon Lightfoot, of London's Metropolitan Police, said the thief appeared to have "specifically targeted" the stolen works. Other pieces hanging in the gallery were left untouched.
The suspect broke in by forcing open the front doors, before taking "Oleoylsarcosine" and "Pyronin Y" off the wall and driving away with them in a dark-colored hatchback.
"The items would have been visible in the back of the car and we are appealing for any witnesses or anyone with information to please come forward," Lightfoot said in a statement.
"Oleoylsarcosine" was created in 2008; it measures 67cm by 89 cm and is worth $29,480 (£18,000). "Pyronin Y", which dates from 2005, measures 103cm by 116cm, and is worth $24,565 (£15,000).
Both pictures are part of Hirst's extensive series of spot paintings, rows of randomly-colored dots on a white background, the majority of which are painted by Hirst's assistants, under his direction.
The group, many of whose members met while studying at London's Goldsmiths university, was championed by art collector Charles Saatchi.