The explosion happened Wednesday at the West Fertilizer Co. in the town of West. Fourteen people were killed and a number of homes were destroyed, CNN reported.
Evacuated residents were told Saturday that they could return to their homes, officials said. It was unclear how many West residents were displaced following the explosion.
"I want to dispel any rumors of any health or safety hazards or threats at this time in the city of West," Mayor Pro Tem Steve Vanek said. "It is safe, it is safe, it is safe for our citizens."
Residents who were allowed to return to their homes were warned that their access to water, electricity and natural gas will be limited and that they would be subjected to a curfew from sunset until 7 a.m.
Local officials were working with federal authorities to figure out what caused explosion, Gov. Rick Perry said Friday.
"It's going to be a long recovery for this community," Perry said.
Meanwhile, state fire marshals and the Bureau of Alcohol Tobacco Firearms and Explosives have completed their investigation "on certain parts of the affected area," Vanek said, adding that arrangements were being made for insurance officials to assess the damage, CNN reported.