TYLER — More illegal tire-flattening devices have been found on Interstate 20.

The devices known as “caltrops” were located Tuesday morning in the westbound lanes at the U.S. 69 on-ramp in Lindale, near the Hideaway and the Texas 110 exits, and also in the eastbound lanes near the Hideaway on-ramp.

Caltrops are multipronged devices, about 3 inches in size, made of welded rebar and sharpened on each prong. Whichever way the device lies, a side points up so that it will stick into a tire and cause it to flatten or blow out.

Law enforcement and the Texas Department of Transportation continue to search for people responsible for making the spiked devices, which also had been found about two weeks ago.

During a July 8 press conference, Texas Department of Transportation spokeswoman Kathi White said more than 300 caltrops had been picked up at that time along the 12-mile stretch on I-20 between U.S. 69 in Smith County and FM 314 in Van Zandt County.

She encouraged people to use caution while driving.

Smith County Sheriff’s Office spokesman Sgt. Larry Christian said caltrops are considered a dangerous road hazard because of the possibility of a blowout spurring a wreck that could lead to injuries or death.

Caltrops and other tire-flattening devices are illegal weapons under the Texas Penal Code. A person can be charged with a state jail felony if they intentionally or knowingly possess, manufacture, transport, repair or sell a tire-deflation device.

If a driver experiences a blowout and believes a caltrop was involved, Christian said the driver should notify law enforcement.

The sheriff’s office asks anyone who knows about the manufacture or distribution of caltrops to call (903) 566-6600.