Twisters and funnel clouds were spotted across Oklahoma on Monday. The latest round of severe weather came after a weekend full of tornadoes that tore roofs off houses and ripped power lines from the ground.

Following dire warnings from the National Weather Service (NWS), most of Oklahoma, northwest Texas and the eastern Texas Panhandle braced for intense, long-track tornadoes, hurricane-force winds and baseball-size hail.

The NWS pleaded for people to take cover after a large tornado was spotted near the city of Mangum, southwest of Oklahoma City, on Monday afternoon.

Glynadee Edwards, the Greer County emergency management director, told the Associated Press some homes suffered roof damage, the high school's agriculture barn was destroyed but the livestock survived.

"The pigs are walking around wondering what happened to their house," she said.

519 PM - large tornado now 3-4 WSW of Mangum. Capable of producing extensive damage. Take cover NOW! — NWS Norman (@NWSNorman) May 20, 2019

Twenty minutes later, the agency reported another twister had formed in the nearby town of Granite.

Video of the tornado near Mangum showed a massive twister spinning through rural areas and towering over homes.

There were no immediate reports of injuries. The state Department of Emergency Management said "numerous" power lines were down and a few homes and an apartment complex had been damaged.

The department said in a statement there were roughly 2,000 power outages across Oklahoma, with most of them in the eastern part of the state. Highways deluged by rain had been closed, the statement said, adding that flooding was expected to continue overnight.

In the northern part of the state, Mike Honigsberg, director of the emergency management agency in Garfield County, said he hadn't seen any evidence of tornado damage, but 3.5 inches of rain on Monday had washed out roads around the county.

“We are encouraging folks not to travel into unfamiliar areas and do not drive around barricades," he wrote. "We have had several water rescues and we’ve rescued folks who have driven into really bad areas."

Possible hail and winds reaching 70 mph were expected as a squall moved across the state, he added.

In Peggs, Oklahoma, a community east of Tulsa, the fire department said that a storm Monday “caused widespread damage and has made most roads very hazardous,” with some being impassable. “Do not travel in Peggs if you don't have to,” Peggs Fire-Rescue said in a statement.

A meteorologist with the NWS in Norman, Oklahoma, said earlier on Monday that the storm could be extremely dangerous.

"We're underway with watches and warnings in what will be a non-stop 24 to 36 hour onslaught of severe storms, flooding and tornadoes," said the meteorologist, Rick Smith. "Many of us will get multiple rounds of severe weather, and flooding will be disastrous for some."

The National Weather Service said on its website late Monday that a swath from central Texas, across southeastern Oklahoma, northwestern Arkansas and southern Missouri were under tornado watches. Other parts of Oklahoma and Missouri were under flash flood warnings

As many as 67 tornadoes were reported from Friday to Sunday in Texas, Oklahoma, Louisiana, Kansas and Nebraska.

The storms and extreme weather warnings fall on the sixth anniversary of the tornado that tore through the Oklahoma City suburb of Moore in 2013, killing 24 people and injuring 212 others.

The storms also come just a few days before the eighth anniversary of the tornado that devastated the town of Joplin, Missouri, in 2011. The Joplin tornado, which killed 158 people and injured more than 1,000 others, is the deadliest since modern record keeping began in 1950 and is ranked seventh among the deadliest tornadoes in U.S. history, according to the NWS.