DETROIT (CBSDFW.COM/AP) — Safety regulators in the United States are investigating reports that side air bags can inflate for no reason on some Mazda CX-9 SUVs.

Documents posted Monday by the National Highway Traffic Safety Administration say two owners have complained about the problem. In one of those cases four people were hurt.

In both complaints owners of the large SUVs told the agency that the left and right air bags went off for no reason while the SUVs were moving.

The probe covers CX-9s from the 2010 through 2013 model years. Mazda sold just over 112,000 of the SUVs from 2010 through 2013.

The safety agency says investigators will figure out how often the problem happens and determine the safety consequences. The agency could seek a recall.

Messages were left Monday morning seeking comment from Mazda.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)