In addition, 16 people were found alive and transported to hospital.
The bodies of 46 people have been found in a heavy vehicle trailer in the state of Texas, Texas, says the head of the San Antonio Rescue Department Charles Hood at the press conference.
According to the police chief, a further 16 people were found alive and transported to hospital. Four of those found alive were minors.
Police commissioner William McManus San Antonio police said at the same news conference that three people have been arrested in connection with the case.
According to the Texas Tribune, the trailer was found near the Lackland Air Force base on the west side of San Antonio.
Authorities say the dead are believed to have been migrants who have crossed the border between Mexico and the United States illegally.
The causes of the deaths are not yet known, but temperatures in San Antonio in June have approached all-time highs, the New York Times reports. On Monday, the temperature in the city was almost 40 degrees.
According to the New York Times, the number of illegal border crossings has grown to a record high on the Texas-Mexico border. Last month, 44,000 people crossed the border illegally through the border towns of Del Rio and Eagles Pass, which are the closest border towns from San Antonio.
The trailer found was nearly 200 miles from the border.
“These Deaths are the result of his deadly open door policy,” Abbott wrote in his tweet.
26.6 at 7.01 Corrected. Charles Hood is the chief of the rescue service, not the chief of police, as he read earlier.