People are evacuated from Cinergy Odessa cinema following a shooting in Odessa, Texas, U.S. in this still image taken from a social media video August 31, 2019.   Rick Lobo via REUTERS   ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES.
People are evacuated from an Odessa movie theater following a shooting in Odessa, Texas, in this still image taken from social media video Aug. 31, 2019.

Last update: Sept. 1 at 2:02 p.m.

Texas police say the death toll from a mass shooting in the western part of the state Saturday has risen to seven, with at least another 20 injured.

The gunman was also killed. His motives remained unclear.

Odessa Police Chief Michael Gerke called it a "horrific day" after the shooting deaths in Odessa and nearby Midland, Texas.

Police said the incident started when a suspect hijacked a U.S. Postal Service mail vehicle, then drove around randomly firing at people.

The shooter, described as a white male in his 30s, was shot and killed after being trapped by police in the parking lot of a movie theater, authorities said. They did not provide a motive for the attack, in which three police officers were also injured.

Gerke declined to name the gunman.

Odessa-Midland, TX

President Donald Trump on Sunday praised police in Texas for their handling of the latest mass shooting rampage in the U.S., calling it "a very tough and sad situation!" It was the third such U.S. mass killing in August, following the shooting deaths of 22 people in El Paso, Texas, and nine in Dayton, Ohio.

Trump said he is speaking with Republican and Democratic lawmakers about legislative efforts to curb the frequent mass shootings in the U.S. But the U.S. leader said he does not believe heightened background checks for gun buyers, which numerous lawmakers are calling for, would "have stopped any of it."

"I think Congress has got a lot of thinking to do frankly," Trump said. "They've been doing a lot of work. I think you're going to see some interesting things coming along."

The acting Homeland Security chief, Kevin McAleenan, told ABC's "This Week" show that the spate of recent killings "are absolutely a homeland security threat."

Texas Governor Greg Abbott released a statement Saturday, saying: "The First Lady and I are heartbroken over this senseless and cowardly attack, and we offer our unwavering support to the victims, their families, and all the people of Midland and Odessa. The state of Texas and the Department of Public Safety are working closely with local law enforcement to provide resources as needed and deliver justice for this heinous attack."

Saturday's shooting comes after the mass shooting in early August at an El Paso, Texas, Walmart, where many of the 22 victims were Hispanic, targeted by a gunman who allegedly told police he wanted to shoot Mexicans. He is being held on murder charges.

The El Paso shooting occurred 13 hours before a gunman in Dayton, Ohio killed nine people in a nightlife district before police shot him to death. The double mass shooting within hours of each other led to calls for stricter gun control measures in the United States, but such legislative efforts have failed in the past as the outrage over the killings quiets as time passes.

Former Texas congressman Beto O'Rourke, who lives in El Paso, reacted shortly after news broke of the shooting in Odessa, which is 455 kilometers east of El Paso.

"We need to end this epidemic," O'Rourke tweeted on Saturday.

O'Rourke, who is also a Democratic presidential candidate, expressed sympathy with "everyone in West Texas who has to endure this again."