FEMA is warning victims of the devastating flooding in southeastern Texas of a scam involving robocalls that tell people they're overdue on their flood insurance premiums and need to make an additional payment to have coverage for Hurricane Harvey.

Roy Wright, FEMA's deputy associate administrator for insurance and mitigation, said there have been reports of a robocall intended to extort money out of people whose homes have flooded in the wake of Hurricane Harvey.

"That is pure fraud," Wright said Thursday morning. "You should only be taking trusted information from trusted sources."

Wright reminded people to only trust the information coming from their insurance agent or company, local officials and the adjusters they assign, or FEMA officials.

"If they are not a trusted resource, do not rely on them for information," he said.

In the wake of Hurricane Harvey, which brought record-setting rainfall to southeastern Texas and left thousands of people displaced, federal officials have been sounding the alarm on scams targetting flood victims.

Immigration and Customs Enforcement warned Houston-area homeowners Wednesday that people were impersonating federal officials and knocking on doors, then telling residents to evacuate and robbing their empty homes.