LITTLE ROCK, Ark. » The Arkansas Senate voted Thursday to prohibit most abortions if a heartbeat is detected, ignoring warnings from opponents that banning the procedure as early as six weeks into a pregnancy would invite lawsuits.

If enacted, the ban would be the most stringent in the nation. The Ohio House passed a similar ban in 2011, but it was sidelined in the Senate last year over concerns it might be found unconstitutional. Demo­cratic Gov. Mike Beebe said Thursday that is the concern that he’s researching.

"I’m waiting on lawyers. I think that’s the big concern right now: Does it run afoul of the Supreme Court or constitutional restrictions?" Beebe said. "That’s the first thing we’re looking at."

The Senate approved the new ban the same day that a House committee advanced two other abortion restrictions, part of a package of legislation anti-abortion groups believe is poised to become law now that Republicans control the state General Assembly.

The Senate approved the proposed Arkansas Human Heartbeat Protection Act by a 26-8 vote. The measure, which now heads to a House committee, requires a test to detect a fetal heartbeat before an abortion is performed. If one is detected, a woman could not have an abortion, except in cases of rape and incest, and if a mother’s life is in danger.

Similar legislation is also being considered in North Dakota and Mississippi. All have faced complaints from abortion rights groups that it runs afoul of the U.S. Supreme Court’s 1973 Roe v. Wade ruling that legalized abortion up until viability, usually at 22 to 24 weeks.

A day earlier an attorney for the American Civil Liberties Union said the group would sue the state if it enacted the new restriction. Opponents have also said that the only way to detect a fetal heartbeat at six weeks is by using a vaginal probe.

The bill could go before the House Public Health Committee as early as next week, but its fate is uncertain. Demo­crats control 11 of the 20 seats on the panel, and Republicans hold only a 51-seat majority in the 100-member House.

Though the Legislature has considered abortion restrictions in recent years, most proposals haven’t made it to the governor’s desk under Demo­cratic majorities. Beebe, however, has backed some abortion restrictions. He signed into law a proposal two years ago placing new regulations on the clinics that offer the abortion pill, and in 2009 he signed legislation that mirrors a federal law banning late-term abortions.