According to Mower County Sheriff Terese Amazi, two anhydrous ammonia tanks that leaked Monday do not appear to have been tampered with.

The two anhydrous ammonia leaks caused Interstate 90 to be shut down and homes to be evacuated Monday night.

Amazi confirmed two 1,000 gallon anhydrous ammonia tanks leaked from burst hoses — one while being towed by a farmer and the second about two miles away at a grain elevator on County Road 7 south of Elkton sometime before 5 p.m. Officials checked over the tanks Thursday but did not find evidence they were tampered with. Officials are still looking into the tanks.

After Monday’s leaks, a perimeter was set up around Elkton and some homes were evacuated near the incident. Farmers use anhydrous ammonia for fertilizer, but it’s a toxic chemical that can burn and be harmful to eyes.

Several firefighters and a deputy were exposed to the chemical and sustained minor injuries after the cloud changed direction unexpectedly. No other injuries were reported.

Dexter and Grand Meadow Fire Departments also responded to the scene.