The governor of Texas has signed a law banning abortion from as early as six weeks - before most women know they are pregnant, BBC reports. 

Governor Greg Abbott signed the legislation at a ceremony on Wednesday.

It bans abortions after the detection of what anti-abortion campaigners call a foetal heartbeat, something medical authorities say is misleading.

The law is also unique in giving any individual the right to sue doctors who perform the procedure past this point.

Doctors and women's rights groups have heavily criticised the law, which will take effect in September if it is not stopped by a court.

Texas is the latest and largest US state to pass abortion restrictions.

It comes just days after the US Supreme Court agreed to hear a case which could upend the nationwide legal right to abortion, laid out in the landmark 1973 Roe v Wade ruling. A ruling could give individual states greater powers to restrict abortions.

News.Az