A federal judge Monday rejected as unconstitutional an Alabama law requiring doctors at abortion clinics to have admitting privileges at local hospitals.

The requirement, adopted by the Legislature in 2013, would have forced three of Alabama’s five abortion clinics to close, severely restricting access to abortions while not providing significant medical benefits, U.S. District Judge Myron Thompson wrote in a 172-page decision.

“The resulting unavailability of abortion in these three cities would impose significant obstacles, burdens, and costs for women across Alabama,” he wrote.

Thompson extended an earlier order blocking enforcement of the law and said he would issue a final order after considering more written arguments from lawyers.

Major national medical associations have said that requiring admitting privileges is medically unnecessary because in the rare emergency, hospitals will accept patients and specialists will provide treatment.

Clinics in Birmingham and Mobile run by Planned Parenthood Southeast and the Montgomery clinic, and operated by Reproductive Health Services, filed the lawsuit, saying they would have to close because they use out-of-town doctors without admitting privileges and have been unable to get local doctors with privileges to serve their clinics.

New doctors are unlikely to begin performing abortions in the state because of the “detrimental professional consequences” of being associated with the procedure and because of a history of violence associated with it that includes bombings, shootings and arsons against clinics across the South, the judge said.

In Alabama, Thompson wrote, a clinic in Tuscaloosa was firebombed and workers have been followed in their cars. Eric Rudolph killed a police officer and critically injured a nurse when he detonated a bomb outside a Birmingham clinic in 1998.

The ruling adds to a swirl of contradictory court decisions on the requirement of admitting privileges, especially in the South where abortion opponents have promoted such laws in the name of patient safety. Advocates of abortion rights call the requirement a transparent effort to close clinics.

A similar law in Mississippi that would have shut down the state’s sole abortion clinic was overturned last week by a federal appeals court. In that case, a panel of the 5th U.S. Circuit Court of Appeals in New Orleans did not rule on the disputed claims about medical safety. Instead, it said the state had to maintain the right to abortion within its borders.

In a U.S. District Court in Texas on Monday, two clinics that were forced to close because of a similar admitting privilege rule, which was upheld by a different 5th Circuit appeals panel, are mounting a new challenge. In the same court, clinic owners also seek to block a law imposing costly surgery-center standards that take effect Sept. 1. That law could reduce the number of clinics in Texas to fewer than 10, from about 19 now operating.

Thompson, who is based in Montgomery, Ala., and is a 1980 appointee of President Jimmy Carter, rejected Alabama’s argument that admitting privileges were needed to provide continuity of care in emergencies and to ensure that doctors had up-to-date credentials. He found that clinics in Montgomery, Birmingham and Mobile could not meet the rule because their doctors do not reside locally, a requirement of nearby hospitals.

If these clinics were forced to close, abortion would be available only in Huntsville and Tuscaloosa, imposing a serious obstacle, he ruled, to women in much of the state.

“If this requirement would not, in the face of all the evidence in the record, constitute an impermissible undue burden,” Thompson wrote, “then almost no regulation, short of those imposing an outright prohibition on abortion, would.”

Similar laws about admitting privileges have been blocked by federal courts in Mississippi, Kansas and Wisconsin, while they have taken effect in Missouri, North Dakota, Tennessee, Texas and Utah.

In a statement, Alabama Attorney General Luther Strange said he disagreed with the ruling and would appeal after Thompson issues a final order.

Gov. Robert Bentley said in a statement that “we are extremely disappointed by today’s ruling.”

“I will always fight for the rights of the unborn, and support an appeal of today’s decision,” he said.

Information for this article was contributed by Erik Eckholm of The New York Times and by Jay Reeves of The Associated Press.