(Reuters) - Detroit, currently under post-bankruptcy state oversight, is planning to sue mostly banks and for-profit companies for some $12.2 million dollars in unpaid taxes from investment properties they purchased, the city said on Wednesday.

Nearly 600 lawsuits will be filed later this month mainly in Michigan District Court in Detroit to recover tax money owed from 2010 to 2012 on 1,543 properties if demand letters the city sent this week to property owners do not result in payment.

Detroit said it plans to go after delinquent taxes for other years with a subsequent effort.

“We are working to improve city services for our residents, and to do that – whether it’s better police and fire protection, street lights or better schools for our children – we need everyone who does business in this city to pay their fair share,” said David Szymanski, Detroit’s treasurer and deputy chief financial officer, in a statement.

Detroit exited the biggest-ever U.S. municipal bankruptcy in December 2014, shedding about $7 billion of its $18 billion of debt and obligations. The city aims to be released from post-bankruptcy state oversight by January 2018, according to Mayor Mike Duggan.

Szymanski said the lawsuits will not target individuals who live in their homes or own fewer than three properties.

“We went to great lengths to ensure that we were going after only those who bought property as investments, not as a place to live,” he said.

An abundance of cheap properties fueled buying by U.S. and overseas investors hoping to make money from Detroit’s resurgence.

Real estate marketplace Zillow pegs the median home value in Detroit at $37,400, less than half of what it was 10 years ago.