Authorities in Florida are concerned about an alarming increase in the number of people overdosing on the synthetic marijuana drug known as Spice.

Tampa TV station WTVT reports authorities are concerned that a bad batch of the drug might be circulating, after police in Tampa noted an uptick in the number of people overdosing on the drug. Investigators in Clearwater similarly said they've recently received dozens of calls about people needing hospital emergency room treatment after using the drug.

Homeless Community Hit Hard

There were at least three instances of people overdosing on the drug on March 16 alone. The incidents took place around the Crest Lake Park area, which is heavily populated by the homeless.

A photo made public by the Clearwater Police Department shows a group of three who had all just used the drug. Two are seen slumped over and the third is sprawled across the pavement. In a video shot in the same area, Major Eric Gandy can hardly get a response from a group of users reduced to a zombie-like state.

"The spike that we're seeing and my personnel are dealing with on the road are unprecedented," said Gandy. "Looked like one of our zombie movies."

Some Users Become Violent

Not everyone seems to respond to the drug in the same way. Reports are police have also encountered some individuals who have become more violent after smoking Spice. The outbreak is proving to have a serious impact on the area's emergency services personnel.

'We have noticed a serious uptick of Spice incidents lately that have turned into medical calls, and it's become a serious drain on resources for the police department, for the fire department, and then in turn for doctors at Morton Plant Hospital where the patients end up," police spokesman Rob Shaw told WTVT.

"You wonder when somebody's going to have a heart attack and die from some of these substances," he added.

Meanwhile, the St. Petersburg Police Department added dispatchers have answered several calls of Spice users needing medical assistance over the last several days.

Police warn that individuals who supply the synthetic drug may be changing the ingredients, leaving users unsure just what it is they're smoking.