A Texas man is accused of booby-trapping toilets in the bathrooms of two car washes with "pressure-activated" fireworks.

Paul Moses Alden, 46, was arrested Aug. 1 on a charge of "arson causing reckless damage – bodily injury," the San Antonio Police Department said. He was released from jail the same day on $50,000 bond. 

Alden allegedly placed fireworks under restroom toilet seats, which caused injuries when a person sat down, police said. 

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A car wash

A sign for The Wash Tub in San Antonio, Texas, where people were injured by toilets rigged with small explosives, police say. (Google Maps)

A police affidavit cited by KENS 5 said multiple people were hurt when the fireworks detonated. 

The first incident was reported July 20 at The Wash Tub, a car wash in Helotes, Texas. A man was seen on surveillance video entering a unisex bathroom before a small explosion occurred. A woman was injured, authorities said. 

Six days later, a girl and an employee at a Wash Tub in San Antonio were injured from exploding devices attached to a toilet seat. Remnants from the fireworks were found in the bathroom, police said. 

In each case, authorities say, Alden was captured on security cameras entering and leaving the bathroom, sitting in the lobby watching the bathroom door and then leaving the area after the explosions. Employees said they were able to identify him because he is a regular at the car wash who used his membership card. 

Bathroom and toilet

A Texas man is accused of booby-trapping toilets in the bathrooms of two car washes. (Smith Collection/Gado/Getty Images)

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"We are very pleased with the quick action of SAPD and the arson investigator working this case," a spokesperson for the car wash chain told the TV news outlet. "We will continue to fully cooperate with SAPD and the district attorney's office."