Updated

Several families have filed a class-action lawsuit against the state of Michigan and the Flint school district, saying more needs to be done to help students whose academic performance and behavior have worsened since drinking the city's lead-tainted water.

The lawsuit, filed Tuesday in federal court, says there "has been no effective response" to the lead-related problems faced by children in Flint's public schools. Families say the state Education Department, the Flint district and a countywide district are not complying with laws intended to help disabled students.

The state declined to comment. There was no immediate response from Flint.

While Flint used the Flint River as a water source for 18 months, lead leached from old pipes because the water wasn't properly treated. Lead affects the brain and nervous system.