A gunman opened fire Saturday in a Walmart and around a nearby shopping mall in El Paso, Texas, leaving 20 people dead and 26 injured, law enforcement officials said.

In delivering an updated number of deceased, Gov. Greg Abbott called it “one of the most deadly days in the history of Texas.”

“Twenty innocent people from El Paso have lost their lives,” he said.

Authorities appealed for urgent blood donations for the wounded.

One suspect was in custody, officials said.

Law enforcement sources say police identified the suspect as Patrick Crusius, 21, from the Dallas area. Sgt. Robert Gomez of the El Paso Police Department said no shots were fired by law enforcement.