A group of Democratic lawmakers from Texas on Tuesday urged the state's Republican governor to halt his aggressive border security campaign after a report alleged that Texas authorities were ordered to deny water to migrants in extreme heat and to push migrant children back into the Rio Grande River.

The lawmakers, led by Representative Joaquin Castro, called on Democratic President Joe Biden to use federal authority to halt Texas Governor Greg Abbott's border security efforts if Abbott refuses to stop the initiative, called Operation Lone Star.

Castro said the Justice Department should complete an ongoing investigation into possible civil rights violations under the Texas operation and issue a cease-and-desist order, calling Abbott's policies "brutal" and "inhumane."

In recent months, Texas National Guard troops have strung up razor wire to block migrants from crossing the Rio Grande from Mexico to Texas.

Last week, Texas authorities began installing a floating barrier in the middle of the river near Eagle Pass, Texas, sparking a diplomatic complaint from Mexico.

A State Department spokesperson said Texas had not consulted with federal officials before installing the buoys or barriers.

The number of migrants caught crossing the U.S.-Mexico border illegally has dropped since Biden implemented a restrictive new asylum policy in May. Even so, roughly 100,000 were apprehended in June.

The allegations that Texas authorities gave orders that put migrants in potentially life-threatening situations were reported by the Houston Chronicle, which cited an email from a Texas Department of Public Safety paramedic and trooper.

In a joint statement, Abbott and other Texas officials defended their border security strategy.

"No orders or directions have been given under Operation Lone Star that would compromise the lives of those attempting to cross the border illegally," they said.

The officials added concertina wire and other deterrent measures discourage "potentially life-threatening and illegal crossings."