An explosive device was detonated early Saturday outside the Alabama attorney general’s office in downtown Montgomery, Steve Marshall, the attorney general, said in a statement on Monday.

The explosion, which Mr. Marshall said had not injured anyone, was set off one day after he announced that he did not plan to prosecute I.V.F. providers or families seeking treatment after a recent Alabama Supreme Court ruling that frozen embryos are legally considered children.

The statement did not say whether the explosion had caused any damage, whether the motive for the act was known or whether there were any suspects.

“The Alabama Law Enforcement Agency will be leading the investigation, and we are urging anyone with information to contact them immediately,” Mr. Marshall said in the statement.

A spokeswoman from the attorney general’s office said on Monday that she could not provide any information beyond the statement, and directed further questions to the Alabama Law Enforcement Agency. The agency did not immediately respond late Monday afternoon to a phone call and email seeking comment.

The Alabama Supreme Court ruling — which was issued earlier this month in appeals cases brought by couples whose embryos were destroyed at a fertility clinic in Mobile — has shaken the world of reproductive medicine, casting doubt over fertility care for would-be parents in Alabama and raising complex legal questions. It has also led some clinics in the state to halt I.V.F. treatments and has left many women in limbo.

On Friday, the attorney general’s office moved to ease some of those anxieties. Mr. Marshall “has no intention of using the recent Alabama Supreme Court decision as a basis for prosecuting I.V.F. families or providers,” Katherine Robertson, the office’s chief counsel, said in a statement.