Officials have closed a high-rise dormitory in downtown Philadelphia in a carbon monoxide scare that sickened several students and sent at least two to a hospital.

Several hundred students at the Art Institute of Philadelphia were forced from the 14-story building before dawn Monday after carbon monoxide detectors went off. The dorm is home to about 550 students.

School spokeswoman Carise Mitch says about a half-dozen students complained of illness after the evacuation. Two went to hospitals and were later released.

The city ordered the building closed until the source of the gas is found. That could take several days. Mitch says the students will be housed at hotels in the meantime.

Two restaurants on the ground floor are also shut down.