Boeing union workers who assemble fighter jets strike in two states following rejection of contract offering 20% general wage increase and $5,000 bonus.

About 3,200 workers at Boeing facilities in St. Louis; St. Charles, Missouri; and Mascoutah, Illinois, voted to reject a labor agreement with Boeing.

The union division that represents about 3,200 workers in Missouri and Illinois on Sunday rejected the aerospace giant’s latest four-year contract proposal, threatening the company’s fragile turnaround effort. The workers went on strike at midnight.