STORY: Residents were urged to keep their windows and doors closed to avoid inhaling smoke.

Firefighters and rescuers worked for four hours to contain the flames in the production building, Brigades of the State Fire and Rescue Service (VUGD) said on Twitter.

California-headquartered Edge Autonomy's website says the company produces "autonomous systems, advanced optics, and resilient energy solutions," to U.S. federal agencies - including the Department of Defense - as well as to U.S. allies.

Two people were hospitalized and police have opened an investigation, LETA reported citing Latvia's VUGD State Fire and Rescue Service.