UPDATED 08/02/11 10:03 a.m.

RIVERSIDE, Ill. (CBS) — Thieves walked off with two air conditioning units at the post office in Riverside over the weekend.

Police came to the post office at 51 E. Burlington St., after employees reported that sometime between closing time Saturday and opening Monday, the two commercial air conditioning units were stolen, Riverside police said.

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Both were bolted to concrete and removed from the scene by cutting the bolts and supply lines.

In addition to the post office, the building from which the units were stolen also houses a dietitian’s office and a jewelry store. An employee of the dietitian’s office says two air conditioning units that were not stolen, but were damaged.

Thus, the entire one-story building is without air conditioning.

The employee described the building as “very, very warm.”

“One person was on vacation, so they were lucky. It was quite warm, and then the jewelry store was closed so they lucked out, but the post office guy, he was cooking in there,” she said.

Police have recovered some evidence and are currently investigating the thefts.

“We are currently searching the business district for any video that may have captured images from the theft,” Riverside Police Chief Tom Weitzel said in a release.

Meanwhile, surrounding villages have also experienced an increase in air conditioning thefts. Window units and commercial units alike are being stolen “at an increasingly alarming rate,” police said in the release.

Police say the thieves are able to remove commercial-size air conditioners in minutes, and likely load them into either large sport-utility vehicles or box trucks.

They park their vehicles in a regular space to appear as if they are parking for normal business.

The stolen air conditioners do not appear to have been taken for scrap metal, police said.

Anyone with information is asked to call Riverside police at (708) 447-2127.

The Sun-Times Media Wire contribute to this report.