Two Dallas police officers were shot and critically wounded Tuesday, the city's police department said.
A civilian also was wounded, the department said, but that person's condition was not known.
Dallas police are looking for a 29-year-old Hispanic man named Armando Luis Juárez in connection with the shooting at a Home Depot, Chief Reneé Hall told reporters Tuesday night.
The man fled in a white pickup, she said.
The incident began Tuesday afternoon, she said, when an off-duty officer at the Home Depot called to request backup officers for an arrest.
The chief asked for people to keep the officers, their families and department in their prayers.
"We need you right now, our hearts are very heavy," she said.
Dallas Mayor Mike Rawlings also tweeted on the shooting: "We are closely monitoring the situation in northeast Dallas and praying for our officers and their families."
No further details were immediately available.
Five Dallas officers were killed and seven others injured in July 2016 when a military veteran who had served in Afghanistan fired on them. The shooter, Micah Xavier Johnson, 25, of Mesquite, Texas, was killed after a lengthy standoff with police.