At least two people were killed and two others were injured when a severe storm destroyed homes and toppled trees in the Florida Panhandle early on Thursday morning, officials said.

Mark Wool, warning coordination meteorologist at the National Weather Service in Tallahassee, said the two people who were killed lived in a mobile home in Washington County that was destroyed early Thursday morning.

“It was the middle of the night and they obviously either didn’t receive the warning or didn’t have any way to shelter from it,” Mr. Wool said. “People in mobile homes really don’t have any protection against tornadoes.”

Mr. Wool said a radar showed a tornado in the area around 4:10 a.m., but the Weather Service could not provide an official confirmation of a tornado until investigators visited the scene on Friday. “We are highly confident that it was a tornado and the damage pictures I’ve seen so far are consistent with that,” Mr. Wool said.

The storm also “severely damaged” a brick home in Washington County and toppled a tanker truck on Interstate 10 in Jackson County, Mr. Wool said.

Kristy Kolmetz, the public information officer for the Washington County Sheriff’s Office in northwestern Florida, said a tornado had caused significant damage.

“There was total destruction of homes, and there were several downed power lines and downed debris on the roadways,” Ms. Kolmetz said.

The Washington County School District closed on Thursday because of the threat of severe weather.

Gov. Ron DeSantis of Florida said on Twitter that his office had received reports of severe weather in Washington and Jackson Counties and that the Florida Division of Emergency Management was there to help local officials.

The high winds and heavy rains in Florida were part of a line of thunderstorms that traveled across the South overnight and into Thursday.

The storms moved east from Mississippi, Alabama and northwestern Arkansas, where at least seven people were injured, two critically, when a tornado touched down on Wednesday.

Mayor Doug Sprouse of Springdale, Ark., the town where the seven people were injured, declared an emergency there on Wednesday. “Many residents have been displaced from their homes and numerous businesses have reported significant damages,” Mr. Sprouse said in a statement.

The Weather Service said the line of storms were continuing to move east on Thursday and could cause severe thunderstorms and isolated tornadoes from Florida to New England.

Bob Oravec, a lead forecaster for the Weather Service, said that on Thursday, “there is a chance for severe weather from the Florida Panhandle across pretty much the entire East Coast.”

Part of the Florida Panhandle, including Tallahassee, and southern Georgia were under a tornado watch Thursday morning that was in effect into the afternoon. The Weather Service said that scattered severe thunderstorms would move east through the afternoon and that wind gusts could exceed 60 miles per hour.

The Weather Service advised people in the affected areas to secure loose items and warned that there could be power outages and downed trees.

More than 16,000 customers in Mississippi, 13,000 in Alabama and 16,000 in Tennessee had lost power as of early Thursday afternoon, according to PowerOutage.US, a website that aggregates data from utilities.