The blaze took place shortly before 1pm local time in Spain following a suspected explosion from the pit box of battery supplier WAE (formerly known as Williams Advanced Engineering).
Team personnel were immediately evacuated as the area was cordoned off at the Circuit Ricardo Tormo.
Following the incident, which is ongoing, Formula E released a statement which read: "Formula E and the FIA are working with the local authorities to contain a fire incident in the Pit Lane.
"The building has been evacuated and there are no reported injuries. More information to follow about Test Session 2 in due course."
The second session of pre-season testing was due to begin at 2pm local time, but no decision has yet been made on whether that will take place.
Mitch Evans set the fastest time for Jaguar in this morning’s session from Porsche’s Antonio Felix da Costa.
More to follow
Source: Autosport