An American school teacher has been stabbed to death in a toilet at a shopping mall in Abu Dhabi. officials say.

The suspect was wearing the traditional black robe, full-face veil and gloves commonly worn by local women throughout the Arab Gulf region, local police said.

A statement posted on the Abu Dhabi Interior Ministry's website said the victim was stabbed with a sharp tool that has been confiscated by police.

The statement said the American woman was 37 years old. Her name has not been made public.

The victim had 11 year-old twins who are now in the custody of police until their father, who is the victim's ex-husband, arrives from abroad.

Col Rashid Borshid, head of the criminal investigation department, said the attacker remains at large. He said police are investigating possible motives and the gender of the attacker.

He said a fight broke out between the victim and the attacker in the women's restroom just before the stabbing, which took place on the upscale Reem Island in Abu Dhabi.

"The Abu Dhabi Police will spare no effort in order to unveil this heinous crime and bring the culprit to justice," he was quoted as saying in the statement.

The US Embassy in the United Arab Emirates said they are aware of the incident that took place and are in contact with Emirati authorities. The embassy said it stands ready to offer all possible consular services.

The UAE is a Western-allied, seven-state federation that includes the glitzy commercial hub of Dubai and the oil-rich capital of Abu Dhabi. It is home to a sizable Western population where foreigners outnumber Emirati citizens.

The UAE prides itself on being a safe haven in the turbulent Middle East. It is part of the US-led coalition conducting air strikes against Islamic State group fighters in Iraq and Syria.