At least 17 people have died in Argentina after consuming cocaine suspected of containing a poisonous substance, with the cases clustered around several towns in sprawling Buenos Aires province, officials and local media said on Wednesday.
Another 56 people have been hospitalized, a government source told Reuters, adding that more are seeking hospital care in eight of the province's municipalities because of the toxic cocaine.
The source said the death toll, from the towns of Hurlingham, San Martin and Tres de Febrero, will likely rise further.
Buenos Aires province, the country's most populous, is home to many suburbs of the national capital.
Officials believe some of the victims suffered from opioid intoxication, according to a statement from the province's health ministry released Wednesday.
The number of those hospitalized with serious illness is "constantly rising," it added.
Provincial security forces detained some people suspected of selling the drug after the first deaths occurred Wednesday.
Some local media outlets reported that the cocaine had been mixed with a toxic substance, likely by a drug gang looking to reduce costs amid a turf war with rival groups.
"We are waiting for the laboratory results and the results of the investigations into the people who have been detained," the province's security minister told local television.
Reuters could not immediately reach the police and courts for further information.
The local government of Tres de Febrero said in a statement it was aware of people falling seriously ill because of "allegedly adulterated cocaine" and was working with emergency services and hospitals to prevent more deaths.
It urged people to discard any drugs bought recently.
"This isn't a normal investigation," San Martin prosecutor Marcelo Lapargo told local news outlet La Naction+, citing expedited police raids aimed at removing all the tainted cocaine. "What mattered most today was to stop the sales to prevent further deaths."