Houston Police Chief Art Acevedo said two people died as a result of the explosion at a northwest Houston manufacturing business early on Friday.
He added that a criminal investigation into the blast's cause was underway, Presstv Reported.
"We have no evidence at this point ... that an intentional act is involved. Having said that, part of our protocol is always to (start) a criminal investigation" in such a case, Acevedo said.
"It's going to take days, if not weeks or months, to get a final determination of what's going on here."
he said people near the blast site should look for debris -- including body parts -- and report it to authorities.
"Please search your homes, and if you can, take a look at your roof," Acevedo said.
According to officials, the explosion took place around 4:15 a.m. local time (5:15 a.m. ET) at 4525 Gessner Road at Watson Grinding and Manufacturing.
A video posted to Twitter showed a fireball rose from the scene after the blast. The distant footage was taken by a camera mounted to a home window.
Debris reportedly flew a half-mile from the explosion site.
“This is still an active scene,” Houston Fire Chief Samuel Peña posted on Twitter. “We will advise of the possible cause of the explosion as soon as we have concrete info.”
Details about what caused the explosion weren't immediately available.
Harris County Sheriff Ed Gonzalez said the blast was felt as far away as 14 miles (22 km), based on social media reports.
"(The explosion) knocked us all out of our bed, it was so strong,” Mark Brady told KPRC television. “It busted out every window in our house. It busted everybody’s garage door in around here. ... It’s a war zone over here.”
Another neighbor identified only as Kim said her family was trapped in her home until rescued, according to Reuters.
“The whole house is ruined,” Kim said. “The whole ceiling crashed down on all of us. We were all trapped in there, and a nice family came and helped us out. It’s trashed. It’s just trashed. ... Every house was devastated.”