Editor’s note: This story has been updated. 

Police found 17 undocumented immigrants inside of a locked tractor-trailer in Texas on Sunday morning, according to Edinburg Police Department police Chief David White.

Police say the undocumented immigrants may have been locked inside of the tractor-trailer for eight to nine hours, according to Edinburg police Assistant Chief Oscar Treviño. They did not require medical attention. 

Edinburg dispatch received a call sometime before 11 a.m. from an unknown individual in Mexico, who reported that a relative was trapped inside of a parked tractor-trailer at the Flying J gas station near Monte Cristo Road.

The caller said the relative was with other immigrants who were battling with the heat inside of the tractor-trailer.   

When police arrived at the gas station, they began knocking on all of the tractor-trailers in the parking lot. Police found 17 undocumented immigrants inside of a locked tractor-trailer after they heard knocking back from the inside. 

Treviño says the undocumented immigrants are from Romania, Honduras, Guatemala and Mexico.

A male and female of Cuban nationality were in charge of the tractor-trailer, and have been detained, according to Treviño. 

U.S. Immigration and Customs Enforcement special agents are investigating the case, and remain at the scene, according to Nina Pruneda, a spokeswoman for U.S. Immigration and Customs Enforcement. 

Edinburg police bought pizza and water for the undocumented immigrants after the rescue.

The discovery comes less than a month after 8 people were found dead inside a tractor trailer in San Antonio, Texas. Two more victims died later in the hospital.

The driver of that rig, James Matthew Bradley Jr., 60 faces charges for his alleged role in their deaths.

Check back for updates.