The U.S. Securities and Exchange Commission has sanctioned five public companies for filing quarterly reports containing financial statements that had not been reviewed by an independent external auditor.

Rule 8-03 of Regulation S-X requires that an issuer must have an independent registered public accounting firm conduct a review of the required interim financial information presented in financial statements included in the quarterly report.

In its first enforcement actions alleging violations of the regulation, the SEC said five companies — Cardiff Lexington Corp., Cool Technologies, Dasan Zhone Solutions, First Hartford Corp., and Infrax Systems — had failed to have their statements reviewed prior to filing 10-Qs.

Each violation of the rule carries a $50,000 penalty. The companies agreed to pay a total of $250,000 to settle the proceedings.

“The commission’s reporting rules are designed to help ensure that investors are provided timely access to reliable interim financial information about public companies in quarterly reports,” Anita B. Bandy, an associate director in the SEC’s Enforcement Division, said in a news release.

“Our data-driven investigative techniques led us to identify these companies, who had deprived investors of the benefit of the external auditor’s involvement by including financial statements in Forms 10-Q that had not been reviewed in accordance with Regulation S-X,” she added.

Cool Technologies, a developer of heat dispersion technologies, had the most violations. According to the SEC, it filed 10-Qs with unreviewed financial statements for two quarters of 2013 and one quarter of 2016.