KANSAS CITY, Mo. — An unmarked FBI vehicle loaded with ammunition and chemicals caught fire Monday morning on 169 Highway. It happened during the morning rush hour and snarled traffic. Firefighters had to keep their distance because of exploding ammunition inside the car.

According to firefighters, car fires can be among the most dangerous. Adding exploding ammunition and magnesium fuel from flash-bang grenades and the danger increases.

A motorist shot amateur video, showing a burning vehicle with a lot of smoke. Dispatchers confirmed the car belonged to a federal law enforcement agency.

“You have the extra added element of needing to be away from that, while those particular components explode go off, whatever they’re going to do,” said Batt. Chief James Garrett. “Then regrouping and fighting that fire.”

Sources said the vehicle burned more extensively than most car fires because of the magnesium, a chemical in flares and flash-bang grenades used by law enforcement tactical teams.

“What magnesium does, when it interacts with water, it acts as an oxidizer,” Garrett said. “So what it does, it makes that fire burn hotter. When you actually add water to it. If those components are there when you fight an initial fire, you have that danger you are encountering.”

The exploding ammunition and magnesium did not cause any injuries to firefighters or those passing by the blaze. The FBI confirmed it was one of their cars that caught fire, saying a mechanical problem was to blame. The agent was not injured.