It will take more time to determine exactly what was in the yellow pills blamed on numerous overdoses in central Georgia. But preliminary tests showed the presence of two synthetic opioids, including a fentanyl analogue, the GBI said Thursday.

So far, at least four people have died and 30 have been hospitalized in the Macon area and in Albany after taking pills that look like Percocet.

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The counterfeit pills have the numbers 10/325 on one side and the word PERCOCET in all capital letters on the opposite side, according to the Bibb County Sheriff’s Office. But the word “PERCOCET” isn’t stamped as deep as the real manufacturer and it’s at an angle, investigators said.

The fentanyl analogue found in the pills has not previously been identified by the GBI Crime Lab, a spokeswoman said.

In Bibb County, 11 overdose cases have been reported, resulting in two deaths, Coroner Leon Jones said Wednesday.

After his sister took a pill, Gregory Mitchell also took one late Monday, Jones said. His sister was admitted to the hospital and should recover.

Mitchell, 52, called 911 when he started feeling bad, but went into cardiac arrest in the ambulance and later died at the hospital, Jones said.

The death of Amirrah Gillens, 36, is also being attributed to the yellow pill, he said.

“I’ve never seen anything like this,” Jones told The Atlanta Journal-Constitution. “It’s gotten our community’s attention.”

Monroe County Sheriff John Cary Bittick said the death of a 21-year-old man there on Sunday may also be attributed to the street drugs.

The funeral was Wednesday for Jackson Carson Moore III, an avid fisherman and Macon native.

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