() A 2020-era scheme appears to be making its way back to the U.S.

Some Texas residents are receiving packages containing mysterious seeds through the mail that they never ordered. The unsolicited packages are usually from China, and although they weren’t harmful the last time, the Lone Star State isn’t taking any chances.

The state’s Department of Agriculture is warning residents not to open the mystery packages and report the items immediately.

Texas Agriculture Commissioner Sid Miller, who issued this warning, told his department “picked up” and “destroyed” about a thousand of the mysterious packages in 2020.

Miller said this time, the packages also contained an “unidentified” liquid.

“That tells me this was probably a test run,” he said. “They’re testing our security, our biosecurity, and seeing if they can get by. And they certainly have.”

Miller advised people that if they receive one of the packages, they should not open the seeds.

“Contact us immediately,” he said. “I’ll get an officer over there, we’ll get an inspector over there, and we’ll pick it up. We will trace and we will identify the package.”