Tornadoes in Mississippi and Louisiana have caused "catastrophic" damage and at least six deaths after touching down Sunday, emergency officials say.

So far, officials say hundreds of structures have been damaged by the storms.

Two people are dead in Lawrence County, Mississippi, according to Monticello Fire Chief Lyle Berard, saying there were reports of two tornadoes in the area.

"It's pretty bad," he said "We have downed trees and multiple homes with major damage."

The Mississippi State Emergency Management Agency confirmed the Lawrence County deaths. It said on Twitter that one person had died in Walthall County and there had been three confirmed fatalities in Jefferson Davis County.

In Covington County, Mississippi, every emergency worker available was working Sunday evening to respond to damage from what the National Weather Service described as "a large and destructive tornado" county Emergency Management Department director Greg Sanford told CNN.

"Where there were houses, they are no longer there," Sanford said, describing the reports of damage in the tiny community of Mount Horeb.

Sanford says the county have received many calls about people being injured but are not yet sure how serious the injuries are.

Tornado watches issued across the South

More than 95 million people in almost 20 states in the South and East are facing the threat of severe weather on Easter Sunday and Monday, with tornado watches issued across areas of Mississippi, Alabama and Louisiana.

CNN meteorologist Gene Norman said a tornado with winds approaching 200 mph had swept through southern Mississippi Sunday afternoon.

"There was a tornado emergency in effect at the time and this tornado was likely on the ground for nearly 100 miles. The Southeast remains under the threat for more multiple, dangerous and destructive tornadoes into the evening as tornado watches are in effect through midnight and will likely be extended eastward by Monday," Norman said.

Candice Pitts rode out the storm in a small hallway at the Soso Volunteer Fire Station in Jones County, Mississippi.

"All I had was my arms to put over my son and mother-in-law," she said. "Was near a solid glass door that blew out and the roof in many places tore off or collapsed. My car was park(ed) under a shed that is now blown over in a yard nearby. It's mangled."

The mayor of Monroe, a city in north-central Louisiana of about 50,000 people, says hundreds of structures in his community were damaged by a Sunday afternoon twister.

"At least 200-300 houses have been damaged here in the city of Monroe alone," Mayor Jamie Mayo said. "We also have had damage throughout Ouachita Parish."

Mayo said there had not been any fatalities reported from the storm, but emergency workers were responding to "minor injuries." Fire crews were also searching damaged buildings to ensure no one was trapped.

The National Weather Service earlier issued its highest level of tornado alert, a tornado emergency, for parts of Covington and Jefferson Davis counties at 4 p.m. (5 p.m. ET). The weather service's Storm Prediction Center said confidence was high that the area was seeing a "strong to intense" tornado with winds of 115-165 mph.

"It is a dangerous day in Mississippi," Gov. Tate Reeves tweeted. "Please take today's severe storms very seriously. The NWS just issued a solemn, rare warning: a 'PDS' (Particularly Dangerous Situation) tornado watch for north central MS until 8pm. Please take precautions to keep your family safe. We are working and watching closely. Stay safe."

Sheltering amid coronavirus

There have been more than a dozen tornado reports across eastern Texas, northern Louisiana and southern Mississippi and a tornado early Sunday was confirmed south of Marble Falls, about 50 miles east of Austin, in Texas the weather service said. It appeared to weaken as it moved northward.

The threat from the storms coincided with the dangers from the ongoing coronavirus pandemic. Officials in Mississippi said most county safe rooms were equipped with hand sanitizer and advised residents to still wear masks in the rooms.

"Social distance as best as possible while inside the safe room," said Malary White, a spokeswoman with the Mississippi Emergency Management Agency.

From a tornado shelter in Starkville, Mississippi, Craig Ceecee told CNN staff were telling people to practice social distancing.

Alabama Gov. Kay Ivey issued a state of emergency ahead of Sunday night's expected severe weather, suspending coronavirus orders where life could be endangered.

"Shelters and community safe rooms should remain open and accessible to all individuals seeking refuge from this severe weather, while implementing reasonable practices and procedures to prevent the spread of Covid-19 among those seeking shelter," she said.

Monroe Mayor Mayo said he had asked local hotels to provide rooms to people made homeless by the storms as coronavirus made opening a shelter potentially dangerous.

Tornadoes touch down in Texas and Louisiana

The city posted photos on its Instagram page showing downed power lines and significant damage to an airport building. "PLEASE AVOID THE AREA as emergency crews do their jobs," the post read.

#sanangelo #severeweather My shed roof flying away. pic.twitter.com/2PSq1NinqD

— Rick (@RickMcGee1) April 12, 2020

Alfonzo Galvan, a journalism student, recorded video of one Monroe neighborhood with debris in the street and several homes with significant damage. He told CNN his family was safe and didn't receive any damage. He lives about 1.5 miles away from the area in the video.

"I got there after the tornado went through the area, but it was just a bunch of people surveying the damage to their homes and looking for their friends and loved ones making sure they were OK," Galvan said.

Louisiana Gov. John Bel Edwards urged residents to stay home.

"Even though the morning storms have left the state, many other dangerous systems remain across Louisiana. Please stay at home, follow the orders of local officials and tune in to your local weather person for updates," Edwards said on Twitter.

"The images and reports of major tornado damage in the Monroe area are heartbreaking, and my prayers are with the people there. We are in contact with local officials in the area to provide support. I hope all of Louisiana is on high alert right now," Edward said in a separate tweet.

As of 7 p.m. ET, more than 138,000 customers in the South were without power as severe weather pummeled the region.

There were 43,741 customers without power in Texas, 39,478 customers without power in Alabama, 36,973 customers without power in Louisiana, and 17,827 customers without power in Mississippi, according to various power companies.

Storm system hit Texas on Saturday

The large storm system that brought severe weather to areas of Texas on Saturday was expected to shift eastward, marring the holiday for many in the Southeast.

Severe weather went through San Angelo, Texas, on Saturday, causing the roof of a shed to fly off.

Strong, long-track tornadoes were forecast for Louisiana, Mississippi, Alabama and Georgia along with strong winds and hail the size of tennis balls or larger.

"Widespread damaging winds are also in the forecast for much of the Southern states," CNN meteorologist Haley Brink said. "Winds this strong have the potential to cause similar damage to some tornadoes."

"These storms are typically warned as severe thunderstorm warnings and not necessarily tornado warnings, which is why it is important to heed all warnings issued by the National Weather Service offices," Brink said.

Get your local forecast for the weekend >>>

Flash flooding is expected in some states in the mid-South, including Tennessee, North Carolina and parts of northern Georgia and Alabama, where rainfall totals could reach up to 8 inches.

Most other areas will receive 3 to 6 inches.

A second wave of severe storms

Meteorologists warn that after a storm passes, residents shouldn't let their guards down.

"For Georgia, we're expecting two possible waves of activity: The first will be in the afternoon on Sunday as a warm front moves through the area," said Kyle Thiem, a meteorologist with the National Weather Service office in Atlanta. "The second wave of storms will likely come through overnight as the main system moves eastward."

By Monday, the system will focus on the East Coast. There will still be a threat of tornadoes, damaging straight-line winds, and hail.

To stay abreast of dangerous conditions, officials advise residents to have multiple methods of receiving severe weather alerts, including weather radio and smartphone apps. For apps, make sure they're not on "do not disturb" or "silent" mode.

If a tornado touches down, sirens will likely sound. However, they're not intended to wake people up; they're meant to alert people who are outdoors that they need to go inside as quickly as possible.