01/17/2012 07:24 EST | Updated 03/18/2012 05:12 EDT

Chevron: Massive fire on offshore rig near Nigeria's coast continues; 2 workers still missing

LAGOS, Nigeria - Chevron Corp. says a fire on an offshore rig near Nigeria's coast is still burning as a search continues for two missing workers.

Chevron said Tuesday it had accounted for 152 workers on the gas rig and a nearby barge after the fire started early Monday morning. The San Ramon, California-based company said two workers remained hospitalized Tuesday with minor burns.

Chevron said an investigation into the fire is ongoing, though they believe a possible equipment failure caused the inferno. Officials with Nigeria's state-run oil company already have blamed the fire on a "gas kick" — a major build up of gas pressure from drilling.

Chevron said it does not know how long the fire will last on the rig, which has partially collapsed.