VAN, Texas — Emergency responders searched through wreckage in parts of Texas and Arkansas early Monday after a line of tornadoes battered several small communities, killing at least two people and injuring dozens of others.

As many as 10 people were still missing at daybreak, raising the possibility that the number of dead could climb.

Two people who lived in adjoining mobile homes in Nashville, Arkansas, were killed after several twisters were reported late Sunday.

Howard County Sheriff Brian McJunkins told KLSA-TV that two other people in the town about 50 miles north of Texarkana were critically hurt.

In neighboring Texas, a likely tornado pummeled the small city of Van. Chuck Allen, the fire marshal and emergency management coordinator for Van Zandt County, said about 30 percent of the community was damaged.

Ten adults were unaccounted for and 26 had been taken to hospitals. The extent of their injuries was not immediately clear. About 50 people stayed overnight at a church shelter, Allen said Monday at a news conference.

The damage ranged “from completely destroyed homes, damaged homes, to trees and power lines down,” Allen said in an email to The Associated Press.

Authorities were going door to door in the city of 2,600 about 70 miles southeast of Dallas, searching for injured people.

Utility companies were working to restore damaged infrastructure, and road and bridge crews sought to reopen streets and highways to provide access to first responders, he said.

The American Red Cross planned to open a shelter at First Baptist Church in Van, Allen said. Calls to the church rang unanswered early Monday.

The Van Independent School District said on its website that schools would be closed Monday.

The National Weather Service believes at least one tornado hit Van on Sunday night, senior meteorologist Eric Martello said. Weather service crews were surveying the area Monday.

Floods resulting from the same storm system that rolled across North Texas caused a huge sinkhole to open up in Granbury, some 40 miles southwest of Fort Worth. The 40-foot-wide sinkhole swallowed the parking lot of a supermarket and damaged water and sewer lines beneath, WFAA-TV reported.

Farther north, in Lake City, Iowa, a suspected tornado tore the roof from a high school as about 150 students, family and faculty attended an awards ceremony inside Sunday night.

Dave Birks, girls’ basketball coach at South Central Calhoun High School, said people were able to flee to the basement and locker room area about two minutes before the twister arrived.

“The lights went off, and everyone’s ears kind of popped,” Birks said, adding that school windows were blown out and insulation was scattered nearby. He also said the high jump pit from the school’s outdoor athletic complex was missing, and hurdles were scattered everywhere.

Much earlier Sunday, storms struck the small town of Delmont in South Dakota, hurting nine people.

“Our house is flat. There is nothing left,” said Stephanie Lunder, 34, who took shelter with her husband and four children in the basement.

The town’s 200-plus residents were asked to leave for safety reasons, state Department of Public Safety spokeswoman Kristi Turman said. They were to be allowed back on Monday to assess their property.

Elsewhere, winter seemed to return briefly to parts of the Dakotas.

The National Weather Service posted winter weather advisories and warnings for southeastern North Dakota and north-central South Dakota, with a couple of inches of snow and strong winds expected. The same area experienced more than 8 inches of snow over the weekend, breaking snowfall records for those dates in Rapid City.

On Sunday, another likely tornado ripped roofs off buildings and damaged trees near Denton, about 40 miles northwest of Dallas. There were no reports of injuries or fatalities.

Torrential rains led to widespread flash flooding. Authorities in Denton County said two groups of people had to be taken by helicopter to safety.