A fire in a bag that cleared screening lines at Denver International Airport and briefly stopped the concourse trains was caused by a vape pen, investigators said Friday.

The fire, caused by a vape pen that had been taken apart, lasted just over a minute around 5 p.m. before a TSA agent grabbed a nearby fire extinguisher and put it out, according to a news release from the airport. No one was hurt.

The bag caught fire just as it was going through one of the bag checking machines at DIA. The vape was taken apart inside a carry-on bag and the lithium-ion battery is thought have made contact with conductive materials inside the bag, DIA officials said. It caused a "dead short" as investigators call it, heating up the combustible materials in the bag until the contents caught fire while going through an X-ray machine.

In a video released by airport staff, TSA agents can be seen reacting and running away from the fire when it first begins. Soon, other soon-to-be passengers notice the small blaze and begin moving away - some faster than others.

It wasn't more than a minute and a half before a TSA agent grabbed a fire extinguisher and put out the small fire.

DIA says the screening process had nothing to do with the fire starting.

Multiple agencies looked into the fire, including TSA, ATF, Denver Police and investigators with Denver Fire.

DIA also attached this statement to the bottom of their news release:

The FAA prohibits electronic cigarettes and vaping devices in checked bags. Under these federal regulations, battery-powered E-cigarettes, vaporizers, vape pens, atomizers, and electronic nicotine delivery systems may only be carried in the aircraft cabin in carry-on baggage or on your person. However, many airlines have policies regarding the possession or use of these devices onboard aircraft. Passengers should know the individual rules of their airline prior to arriving at the airport. Please refer to your respective airline, www.tsa.gov & www.faa.gov for more information.