At least five people were killed and many injured after gunmen hijacked a US portal truck and opened fire randomly in the US state of Texas on Saturday.

Police identified the suspect as a white man in his mid-30s, but could not yet name him or said that why he carried out the attack in the West Texas cities of Midland and Odessa.

“We have at least 21 victims, 21 shooting victims and at least five deceased at this point in time,” Odessa city Police Chief Michael Gerke told AFP.

Three police officers were injured, he said.

The Odessa Police Department had earlier reported that a suspect was “driving around Odessa shooting at random people” and “just hijacked a US mail carrier truck.”

Troopers had initially tried to pull over a passenger vehicle on the Interstate 20 highway but before it stopped, “the male driver (and only occupant in the vehicle) pointed a rifle toward the rear window of his car and fired several shots toward the DPS patrol unit,” the Texas Department of Public Safety said in a statement.

One trooper was wounded, the suspect fled the scene, “and continued shooting innocent people,” the department said.

Last month, 20 people were killed and many injured in a mass shooting at the Walmart store in the US city of El Paso.

In that case, officers arrested Patrick Crusius, 21, a white Texan, who told police that he was targeting “Mexicans,”

The tragedy in El Paso was committed on the basis of “racist” anti-Mexican rhetoric, Jesus Seade, Mexico’s foreign ministry undersecretary for North America, said during a memorial after that shooting.

Earlier in July, US President Donald Trump was criticised for stoking such hatred.

The shooting in El Paso came hours before a gunman in Dayton, Ohio killed nine people, reigniting calls for gun control in the United States where firearms were linked to nearly 40,000 deaths in 2017.