Rescue workers and volunteers searched for more than 1,000 people still missing in the Florida Panhandle and tens of thousands of residents remained without power on Tuesday after the area was devastated by Hurricane Michael last week.

At least 19 deaths in four states have been blamed on Michael which made landfall on Wednesday as one of the most powerful storms on record to hit the continental United States.

Volunteer rescue organization CrowdSource Rescue said its teams were trying to find 1,300 people still missing in the disaster zone in the Panhandle, according to Matthew Marchetti, co-founder of the Houston-based group.

About 30 to 40 people remained unaccounted for in Mexico Beach, according to a city councillor, Rex Putnal.

The mayor of the town of about 1,200 residents, which took a direct hit from the hurricane, has said that at least one person was killed, while CNN reported that another person was found dead on Monday.

With most Mexico Beach homes already searched for survivors, rescue workers were using dogs to find any bodies that might be buried under the debris.