A pension fund for Chicago public employees has voted to divest its holdings in three companies that manufacture assault weapons, an official with the fund confirmed on Thursday.

The Municipal Employees Annuity and Benefit Fund (MEABF) voted on Wednesday to sell off just over $1 million in investments in Freedom Group Inc, Sturm Ruger and Co Inc and Smith & Wesson Holding Corp, MEABF Executive Director Jim Mohler told Reuters.

The move comes in response to the shooting last month at a Connecticut elementary school that left 20 first graders and six educators dead, shocking the nation and sparking a heated debate over gun control in the United States.

The fund delayed making a formal announcement to ensure its exposure to assault weapons makers was limited to the three companies, Mohler said. It joins public pension funds in California, New York and elsewhere that have said they either planned to dump firearms investments from their portfolios or were weighing such an option.

Chicago Mayor Rahm Emanuel, who ordered a review of the city's pension funds last week to see if they were invested in gun makers, welcomed the move.In a statement, Emanuel criticized firearms companies for opposing what he called "common sense" gun safety laws, including criminal background checks on all gun purchases.

Last weekend, at the U.S. Conference of Mayors annual meeting in Washington, DC, Emanuel called on other cities to sever ties with companies that manufacture or sell assault weapons.Earlier in the week, the Chicago Teachers Pension Fund, which has $9.5 billion in assets, voted to divest its $146,000 of investments with gun manufacturing companies.

Other Chicago agencies with investment portfolios, including the Chicago Transit Authority, the Chicago Housing Authority, and the Chicago Park District, are conducting similar reviews of their portfolios, according to City Hall.