Battery-electric trucks were affected by a fire at the Phoenix headquarters of commercial truck manufacturer Nikola Corp. early Friday morning.

Foul play is suspected, according to the company. A vehicle was seen near the trucks just before the fire, Nikola said on its corporate Twitter account. An investigation is underway.

A company spokesperson confirmed the authenticity of the Twitter report. The company said five trucks were impacted.

“Once the situation is further assessed, we will have more information,” Nikola spokesperson Nicole Rose said.

The Phoenix and Tempe fire departments responded to the incident, the company said.

The fire is the latest in a series of setbacks for the beleaguered commercial truckmaker once dubbed the “The Tesla of Trucking.”

Last week, Nikola, announced 270 layoffs, with 150 at its European factory and 120 at its Phoenix and Coolidge, Ariz., facilities. The layoffs came as the company seeks to reduce spending amid a pivot to hydrogen fuel cell vehicles and buildout of a national infrastructure.

Nikola is trying to issue new shares to raise additional capital.

In recent months, the company has dealt with a delivery shortfall, executive turnover and a slide in share prices that led to the NASDAQ warning Nikola could be delisted.

This is a developing story that will be updated as information becomes available.