Two state regulators and a city official have been charged with tampering with evidence and other offences for their alleged roles in the Flint, Michigan, water crisis.
Michael Prysby and Stephen Busch, both of the Michigan Department of Environmental Quality, face multiple felony counts, including misconduct in office, tampering with evidence and conspiracy.
Flint utilities administrator Michael Glasgow is charged with felony misconduct and willful neglect of duty, a misdemeanour.
The charges filed in state court on Wednesday are the first amid the investigation into lead-tainted drinking water in the town.
Michigan Attorney General Bill Schuette said the officials “failed Michigan families”.
“They had a duty to protect the health of families and citizens of Flint,” he told a news conference.
Mr Schuette said he could “guarantee” more charges.
Asked specifically if Michigan Governor Rick Snyder, who has faced calls to stand down over the scandal, was being investigated, Mr Schuette said there is “no target and no one is off the table”.
Mr Snyder told a separate news conference that his office is fully co-operating with investigators, but said he has not been questioned.
The embattled governor added that if the charges filed against the three officials are accurate, it would take the scandal to a “whole new level”.
The crisis began in 2014 after Flint, a working class, mostly African-American city of 100,000 people, switched water supplies to the Flint River from Detroit’s water system to save money.
The water was not filtered properly, which led to lead and other metals leaching from old pipes.
The move sparked a national controversy after blood samples taken from children in Flint showed high levels of lead, which can damage the nervous system.
State officials ignored months of health warnings about the foul-smelling water as residents complained it was making them sick, break out in rashes and lose hair.
Flint returned to using Detroit water in October.
President Barack Obama declared a state of emergency in Flint in January following a request from Gov Snyder.
A congressional committee was also convened on Capitol Hill to investigate the matter.
Mr Synder, who apologised for his administration’s role in the decision to switch the city’s water supply, has accused Democratic lawmakers of “politicising” the crisis.
He announced earlier this week that he would begin drinking Flint water at home and at work for at least a month to assure residents it is safe to use with a filter.