Severe storms and tornadoes ripped through Oklahoma early Sunday, ripping roofs off buildings and leaving tens of thousands of homes and businesses without power in the middle of the night.

Among the many injuries, 11 people required hospital treatment, officials said.

Most of the damage was reported in and around Oklahoma City, near the state seat, but it was also scattered elsewhere in the state.

More than 99,000 homes and businesses in Oklahoma lost power during overnight storms. By late Sunday afternoon, that number had fallen to around 24,000. No deaths were reported.

Richard Thompson, chief forecaster for the National Weather Service Storm Prediction Center in Oklahoma, said he believes six or more tornadoes hit the state overnight. Meanwhile, forecasters warned the state’s residents to be prepared for heavier rains and possible severe weather through Monday.

“We’re not done with this yet,” he said.

Oklahoma City Fire Department spokesman Scott Douglas told the Associated Press that heavy rain and the lingering tornado threat in the early morning darkness complicated early search and rescue efforts. He explained that the first screening was carried out in hard-hit areas around 1.30am.

“It was a heavy downpour. We were trying to scan the area in case a hurricane was coming,” he said. “So that was in the back of our minds, too.”

Mr. Douglas said emergency workers had to rescue two people from an overturned mobile home, including a woman who was injured when an air conditioner fell on her leg.

As daylight broke out, the extent of the damage became apparent. Local television footage showed downed power lines, destroyed homes, overturned vehicles and streets strewn with debris.

Southern Oklahoma Heart Hospital was also damaged, state health officials said.