General Motors Co. is developing a new electric or hybrid car, a company spokesman confirmed Wednesday, following an explosion at the Alternative Energy Center in Warren, Mich., where GM develops batteries for vehicles like its plug-in hybrid Chevy Volt.

The battery that exploded was not being developed for the Volt, but was a prototype battery for a future product, spokesman Greg Martin confirmed.

The Alternative Energy Center develops and tests batteries for hybrid and electric vehicles and is the base for all of GM's battery development.

The company has not confirmed whether the new vehicle will be all-electric or hybrid. But when asked if the prototype battery system was still on the table for the new electric car, Kevin Kelly, GM spokesman for hybrids and batteries, responded that it was too soon to determine.

The company is not, at this time, releasing details regarding its development of a new battery powered vehicle.

The Volt -- which operates as an all-electric car for up to 35 miles, after which it becomes a range-extended electric vehicle with the gasoline engine recharging the battery -- has faced considerable scrutiny in recent months following investigations of Volt batteries catching on fire and a temporary halt in Volt production.

The explosion occurred during extreme testing on a prototype battery, and five employees received medical attention at the scene, GM said in a press release.

One of the five employees injured in the explosion was taken to St. John Hospital and Medical Center in Detroit with injuries that could have been life-threatening, according to Warren Fire Commissioner Wilburt McAdams, the Detroit Free Press reported.

The man was expected to recover, a GM spokesman told the Detroit Free Press. Some 80 workers were evacuated from the battery testing and development facility as smoke wafted through the building.