Leaders from across Texas and the nation reacted Saturday to a shooting at a Walmart in an El Paso mall that left multiple people dead.

Authorities in El Paso have not said how many people were killed but said that one person was arrested after opening fire at Cielo Vista Mall, which is near Interstate 10 on the city's east side.

Democratic presidential candidate Beto O'Rourke, whose hometown is El Paso, was appearing at a candidate forum in Las Vegas on Saturday shortly after news of the shooting was reported. On stage, he condemned gun violence and later posted a message to Twitter, saying in Spanish, "My heart is with El Paso."

ALSO READ: Beto O’Rourke leaves campaign trail to return to El Paso after shooting

Texas Gov. Greg Abbott, President Donald Trump, Vice President Mike Pence and El Paso Mayor Dee Margo are among others who have posted reactions to Saturday's violence. Here is what they had to say.

Mi corazón esta con El Paso en este momento. Tengan cuidado. Por favor todos sigan la instrucciones de los equipos de emergencia.https://t.co/bPAfVU7oPR

— Beto O'Rourke (@BetoORourke)August 3, 2019 

Terrible shootings in ElPaso, Texas. Reports are very bad, many killed. Working with State and Local authorities, and Law Enforcement. Spoke to Governor to pledge total support of Federal Government. God be with you all!

— Donald J. Trump (@realDonaldTrump)August 3, 2019

Adair and I are devastated by the tragic events unfolding in our City. Our hearts go out to the victims and gratitude to our first responders. We will continue to keep you updated.pic.twitter.com/AKzgwtVWgs

— Mayor Dee Margo (@mayor_margo)August 3, 2019 

I’m deeply saddened and troubled by today’s mass shooting in El Paso. It is another tragic, gruesome reminder of the cost of inaction against gun violence. The people of Texas and our nation deserve a Congress that will take action to help prevent this.

— Joaquin Castro (@JoaquinCastrotx)August 3, 2019 

In El Paso, the Texas Dept. of Public Safety is assisting local law enforcement & federal authorities to bring this tragedy to the swiftest & safest possible conclusion.

We thank all First Responders for their courageous response & urge all area residents to remain safe.https://t.co/H6UDwu81SY

— Greg Abbott (@GregAbbott_TX)August 3, 2019 

Saddened by the loss of so many innocent lives in El Paso, TX. Our prayers are with the victims, their families, and the entire community. Grateful for the courageous efforts and swift action by federal law enforcement and local first responders.

— Vice President Mike Pence (@VP)August 3, 2019 

The news out of El Paso is devastating. I'm heartbroken for the victims and their families. Far too many communities have suffered through tragedies like this already. We must act now to end our country's gun violence epidemic.

— Elizabeth Warren (@ewarren)August 3, 2019

Our hearts go out to the families of those killed and injured in El Paso today. We stand with all El Pasoans in the face of this senseless violence, and thank the brave@eppolice officers & first responders. I stand ready to help@ElPasoTXGov and@Mayor_Margo any way I can.

— Senator John Cornyn (@JohnCornyn)August 3, 2019