Updated

Abortion rights proponents have filed a lawsuit challenging a new abortion law in Arkansas that is among the most restrictive in the nation.

The new law bans most abortions from the 12th week of pregnancy onward. The federal lawsuit filed Tuesday says that ban is unconstitutional and seeks to block the law from taking effect this summer. It also asks the court to strike down the law completely.

The legal challenge was filed on behalf of two doctors who provide abortions at a clinic in Little Rock. It comes after state legislators last month overrode Democratic Gov. Mike Beebe's veto to give Arkansas what was then the country's most restrictive abortion law.

North Dakota has since gone further with a law banning abortions as early as six weeks into pregnancy.