LES CAYES, Haiti — Haitians braced for a grim, rising death toll today as help slowly trickled into marooned areas of the country’s southwestern peninsula that was pummeled by Hurricane Matthew, the first Category 4 storm to hit Haiti in decades.

At least 283 people died in just one part of Haiti’s southwest, the region that bore the brunt of the storm, said Emmanuel Pierre, an Interior Ministry coordinator in Les Cayes.

The overall death toll in Haiti is not clear. Authorities expect the number of deaths to increase, with local officials in isolated areas reporting higher numbers. Most deaths are believed to have occurred in the southwest region.

“Devastation is everywhere,” said Pilus Enor, mayor of Camp Perrin, a town near the port city of Les Cayes on the peninsula’s south shore. “Every house has lost its roof. All the plantations have been destroyed.”

Officials were especially concerned about the department of Grand-Anse on the northern tip of the peninsula, where they believe the death toll and damage is highest. The 283 deaths reported by Pierre did not include Grand-Anse or its surrounding areas.