AUSTIN -- Austin-Travis County EMS is responding to multiple calls regarding reactions to K2, or synthetic marijuana, near the ARCH homeless shelter downtown.

ATCEMS said six ambulances and three commanders have evaluated or transported at least five patients.

Officials said they received two calls -- one at 6:30 p.m. and the other at approximately 7:30 p.m.

ATCEMS said that most of the patients were taken to Dell Seton Medical Center and the remaining patients were transported to St. David's Hospital.

This story will be updated as more information becomes available.