Bexar County sheriff's deputies believe they may have discovered a smuggling operation after a high-speed chase in south Bexar County.
Two suspects have been arrested but the search continues for dozens of other people.
As a helicopter searched the brush from above, sheriff's deputies and K-9 units on the ground searched the area surrounding Jett Road in south Bexar County looking for as many as 20 people, some believed to be illegal immigrants.
The situation was the result of a high-speed pursuit that started at Highway 16 and Rockport Road.
The driver of a pickup refused to stop when a deputy tried to pull the vehicle over.
"Because of the number of people in there it looked suspicious," said Sgt. Chris Burchell. "He ran the license plate and it came back stolen. When he turned his red lights on, they took off running."
The pursuit went east on Loop 1604 before the vehicle turned on to Jett Road.
That's when investigators say the driver made a desperate and dangerous attempt to escape.
"The individual he was pursuing drove off into the brush at a high rate of speed, crashed a gate, went about 100 yards into the brush," said Burchell.
The deputy was forced to follow the suspects on foot after his car got stuck in some bushes and caught fire.
The suspects' vehicle and two more sheriff's vehicles also got stuck in sand.
Investigators say dozens of people fled the scene. Modifications made to the truck suggest it may have been used for smuggling.
Investigators say the two people taken into custody will be charged with evading arrest. However, given the circumstances and the suspicious changes made to the truck, an immigration hold has been placed on the suspects to allow federal investigators time to interview them.