Heavy rains continued to pummel the South on Thursday morning, spurring concerns about more flash flooding in states that have already received more than nine inches of rain this week.

The National Weather Service had issued new flash flood warnings for portions of Texas, Arkansas, Mississippi and Louisiana, the four states hit the hardest by this week’s storms.

It also issued numerous other flood warnings and flash flood watches in the Mississippi and Ohio valleys as the storms threatened to bring multiple inches of rain today and tomorrow.

National Weather Service storm reports indicate that Northern Louisiana has seen the heaviest rains since Monday, with more than 17 inches falling at Monroe Regional Airport as of 9 a.m. Thursday. More than 14 inches fell in Bossier City, and Shreveport received more than 10.

Louisiana Governor John Bel Edwards declared a state of emergency in 16 parishes affected by the severe weather. One of them was Bossier Parish, where the local sheriff’s office reported that a mandatory evacuation was ordered for at least 1,000 homes as the Red Chute Bayou rose.

The National Weather Service’s office in Shreveport said that evacuations also occurred in Haughton and Minden, and the floods led to “numerous” road closures and high-water rescues.

Texas, Mississippi and Arkansas also had at least one community where nine or more inches fell, and those states were all experiencing some degree of flooding on Thursday.

The National Weather Service website showed dozens of river gauges in those states were at flood stage, adding that “major flooding” in at least six locations in Texas and Louisiana. Dozens more were near flood stage, and the additional rainfall threatened to push water levels higher.

The heaviest rains are expected along the southern banks of the Mississippi River, and the service said parts of Mississippi and Louisiana could receive five or more additional inches.