Americans in Abu Dhabi on alert after teacher slaying

The State Department is warning American citizens traveling or living in Abu Dhabi to keep "awareness" levels high after the slaying of an American teacher this week.

The security warning from the State Department's Overseas Security Advisory Council reminded Americans to be "vigilant" of their surroundings and encouraged them to vary routines and schedules.

The warning comes after Abu Dhabi police on Thursday detained a woman in connection with the stabbing death of kindergarten teacher Ibolya Ryan, whose body was found Monday in the bathroom of the Reem Island mall in the United Arab Emirates.

Police said the suspect, nicknamed the "Reem Island Ghost," was a woman who wore a black robe and a full-face veil. The suspect, who was not named, also attempted to plant a bomb near the home of an American resident, according to the United Arab Emirates' Ministry of the Interior.

The killing of the 47-year-old mother of 11-year-old twins came a little more than a month after the U.S. Embassy in Abu Dhabi warned Americans of an online posting that encouraged attacks against teachers at American and other international schools in the Middle East.

There's no evidence the mall attack was related to the threat.