TOPEKA, Kan. -- A Kansas judge on Thursday blocked the state's first-in-the-nation ban on an abortion procedure that opponents refer to as "dismemberment abortion."

The decision from Shawnee County District Court Judge Larry Hendricks came in a lawsuit filed from the New York-based Center for Reproductive Rights. The centre represents two Kansas abortion providers and argued the law would force women to undergo riskier procedures or forgo abortions.

The judge said the state's constitution protects a woman's right to have an abortion separately from the U.S. Constitution.

Attorneys on both sides said the ruling is significant and that if his ruling is upheld, the Kansas Supreme Court could grant more protections on abortion than the U.S. Supreme Court does.

Abortion opponents have feared such a result, because they've pushed in recent years for new restrictions.

The judge's order will stay in effect while he considers the lawsuit further. The new law banning the second-trimester procedure was supposed to take effect July 1.

The new law would ban doctors from using forceps, clamps, scissors or similar instruments on a live fetus to remove it from the womb in pieces. Such instruments are commonly used in dilation and evacuation procedures.

The Center for Reproductive Rights said the ban applies to a procedure used in 95 per cent of second-trimester abortions nationally.

The state's lawyers argued that there are safe alternative abortion methods.

Kansas already bans most abortions at or after the 22nd week of pregnancy.

The new law would make exceptions to the ban for preserving a woman's life or preventing serious and permanent damage to her physical health. It also wouldn't apply if doctors ensure that the fetus dies before using instruments to remove it from the womb.