PHOENIX — As the partial government shutdown continues amid negotiations over funding of a border wall on the U.S.-Mexico border, Mexican authorities say they have discovered another drug tunnel.

Mexican police released a video of a 32-foot-long smuggling tunnel that they say runs from Mexico to the U.S. border town of Nogales.

Officials say this is the third tunnel found crossing into Nogales in the past month.

The nearly minute-long video shows two officers inside the tunnel. One of the officers can be heard asking "Is that the exit?" as another officer pushes open what appears to be a hatch.

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According to the video, Mexican authorities believe the tunnel was being used to smuggle drugs and people across the border in Nogales, Sonora.

Authorities did not say how the tunnel was discovered or release its exact location, although at the beginning of the video the officers are seen opening up a manhole as water can be heard running in the background.