Hyundai and Kia are recalling nearly 3.4 million vehicles in the U.S. and urging owners to park them outside due to fire risk.

Hyundai recalled 1,642,551 of its vehicles in the U.S. and 326,942 in Canada, company spokesperson Ira Gabriel told Forbes, due to concerns its anti-lock brake system could leak brake fluid—often indicated by smoking or a burning or melting odor from the car—and result in a fire.

Nearly 3.4 million Hyundai and Kia vehiclesin the U.S. are under recall due to the risk of engine compartment fires.

Hyundai and Kia have recalled nearly 3.4 million vehicles over the risk of an engine compartment fire, warning owners to park their vehicles outside. The U.S. National Highway Traffic Safety

Documents posted Wednesday by the US National Highway Traffic Safety Administration say the anti-lock brake control module can leak fluid and cause an electrical short, which can touch off a fire while the vehicles are parked or being driven.

Hyundai and Kia announced a recall of more than 3.3 million cars due to a fire risk for the affected vehicles.

Hyundai and Kia are recalling more than 600,000 vehicles in Canada and millions more in the U.S. due to a problem with the anti-lock braking system that can start a fire.

Millions of Kia and Hyundai owners are being advised to park outside and away from their homes due to a fire risk, as the National Highway Traffic Safety Administration announces an urgent recall of 3.

Hyundai reported 21 fires in the affected vehicles in the U.S., and another 22 “thermal incidents” including smoke, burning, and melting of parts, while Kia reported 10 fires.

Hyundai is recalling 1,642,551 cars because of an antilock brake module that can leak and cause a fire under the hood. Kia is recalling 1,730,192 cars because a hydraulic electronic control unit (HECU) can experience an electrical short and cause a thermal event.