WEATHERFORD, Texas (AP) – A few hours after the Brazos River subsided enough to allow residents to return to their homes, a new threat of flooding on Saturday may force them to leave again.

The river was expected to rise over flood stage after Brazos River Authority officials opened a fourth flood gate at Possum Kingdom Lake in north Texas on Saturday afternoon.

Parker County officials urged residents to seek higher ground for the night, saying that flood waters could re-enter homes that had been flooded earlier last week. County spokesman Joel Kertok said roads near the river were waterlogged and remained barricaded. “It still could be a deadly situation and that is why we’re strongly urging people to stay out of the water,” he said.

Storms on the southern Plains have claimed 11 lives in Texas starting last week. On Saturday, there were reports of tornadoes touching down in southwest Missouri. No injuries or damages were reported.

In southeastern Kansas, three days of rain led to voluntary evacuations in Iola. “Various sections in the south of town are under water, and the water is climbing,” said assistant city administrator Corey Schinstock. “We have had over 15 inches of rain the last three days. …All the creeks are flooding.”

East of Iola, emergency workers used ropes and a harness to rescue two teenagers trapped on top of a pickup truck. They were trapped for about two hours after the truck became wedged against a tree at a low-water crossing in Crawford State Park, the Crawford County sheriff’s department said.

Lt. Chuck Yokley of the Kansas Highway Patrol said some homes and businesses in Neodesha, Kan., were damaged from flooding and that residents were being told to boil their drinking water.

“Neodesha has limited power, and their water supply is contaminated,” Yokley said.

About 100 people near Marble Falls in central Texas remained stranded for a fourth day. Flood and water damage made roads impassable, said Christa Bromley, a Burnet County Emergency Management spokeswoman. The residents had been notified of the evacuation but chose to stay in their homes near Hamilton Creek.

Authorities said all were safe, and they had power and drinkable water.

Authorities were still searching for two 20-year-old men whose sport utility vehicle was found submerged in a creek Thursday in Burnet County.

Highways across wide areas of Oklahoma remained closed Saturday because of flood damage to roads and bridges.

Showers fell across arts of Texas and Oklahoma on Saturday, and the National Weather Service said more thunderstorms were possible for the two states during the weekend, with a possibility of more heavy rain.

Heavy rain fell to the north and northeast on Saturday and the weather service issued flash flood warnings for parts of Kansas and Missouri.

In Oklahoma City, rainfall was recorded for the 18th straight day Saturday, four days longer than the previous record, set in 1937.

More heavy rain was expected in Oklahoma late Sunday and early Monday as the storm system moved back across the state, combining with a moist air mass lingering over Oklahoma.

“We’re not out of the woods by any means,” weather service meteorologist Kevin Brown in Norman, Okla.,