Retirees, city workers and others waved flags, carried signs and chanted in protest of Detroit's emergency manager and the city's historic bankruptcy filing.
The protest took place Wednesday outside the federal courthouse downtown where a trial is being held to determine if Detroit's bankruptcy can go forward.
One of the chants was: "Hands off our pensions. Make the banks pay."
"We are worried about our health care and our pension money that we were guaranteed when we came on the job," said protester Bruce Porter.
Detroit filed for Chapter 9 protection in July. It's at least $18 billion in debt.
"I'm out here protesting in support of the pensioners and everyone else who is affected by what's going on in Detroit," said Michael Holbrook.
The Rev. Al Sharpton's group, The National Action Network, held a press conference Wednesday afternoon to publicly announce their stance against the bankruptcy filing.
The group vowed there would be more protests.
Special section: Detroit bankruptcy
Rod Meloni column: Is Detroit bankruptcy eligible?
But nothing can happen until a judge finds the city is eligible to be in bankruptcy court.
The trial starting Wednesday is expected to last several days with testimony from state-appointed emergency manager Kevyn Orr and Michigan Gov. Rick Snyder, who authorized the bankruptcy filing.
Related story: Lawyer: Snyder will testify at bankruptcy trial