More fires are expected to ignite at a flooded chemical plant northeast of Houston, its operators said Thursday, after a series of overnight explosions sent a plume of toxic smoke spewing from the site.

"We're anticipating the remaining eight containers that have not yet started to have product degrade in them, for that to start to happen," Richard Rennard, a senior executive with French group Arkema, told a news conference.

"We fully expect that the other eight containers will do the same thing."

Rennard encouraged anyone who has been exposed to the smoke to seek medical advice, while stressing: "It's not a chemical release that's happening. I want to be clear about that. What we have is a fire."