The death toll among dozens of people who consumed cocaine likely laced with opioids in Buenos Aires rose to 24 on Friday, with 23 still in hospital, health officials said.
Eight of the hospitalized are in serious condition and on mechanical ventilation.
Officials said 24 people, aged between 21 and 58, have died since Tuesday night from adulterated cocaine bought from dealers in the poor neighborhood of Loma Hermosa, some 40 kilometers (25 miles) from the Buenos Aires city center.
Most died far from the point of sale, 12 of them at home and two on the road, unable to make it to a hospital on time because of the sudden effects of the tainted drug. Many suffered heart attacks.
Twenty-three remained hospitalized Friday, according to a provincial government update.
Three of them had been discharged but had to be re-hospitalized after taking more of the cocaine, provincial health minister Nicolas Kreplak said.
More than 200 other people sought medical intervention after consuming the substance, presenting symptoms of varying degrees of gravity.
Arrests and seizures
Thirteen people rounded up in a police operation to establish the origins of the tainted drug were due to appear before magistrates as part of the ongoing investigation, according to the Telam news agency.