Detroit ? Teachers overwhelmingly rejected a two-year contract proposal by the city public school district on Sunday and decided to strike.

The Detroit Federation of Teachers, which represents 9,500 employees, said teachers plan to demonstrate at their schools Monday, the day they were scheduled to report to work to prepare for the beginning of the school year.

Classes are scheduled to start Sept. 5. Negotiations were expected to resume Monday.

Union President Janna Garrison said some of the district’s proposals included a 5 1/2 percent wage reduction and copays for health care benefits of up to 20 percent. Only two teachers out of nearly 6,000 voted to accept the district’s proposal, the union said.

The district says it needs $105 million in concessions from its unions, including $88 million from teachers, to balance its budget. The union says Detroit teachers already are among the lowest-paid in the area.