Three Muslim Somali women employed at an Amazon warehouse outside Minneapolis filed a federal discrimination complaint against the company this week, alleging they faced retaliation from managers after protesting their work conditions.

The women say Amazon violated the Civil Rights Act of 1964 by failing to accommodate their religious needs, prioritizing white employees for promotions and retaliating against workers who participated in a rally protesting work conditions.

In a letter with the filing, Muslim Advocates, a nonprofit civil rights group representing the women, accused Amazon of “systemic violations of Title VII” and urged the Equal Employment Opportunity Commission to investigate the allegations.

Muslim Advocates did not name the women in the filing, but one, identified as “Ms. B,” said she stopped taking breaks to pray and use the restroom for fear of falling below a set packing rate.

“Ms. B received her first write-up for falling below the rate during Ramadan, when she was refraining entirely from food or drink,” Muslim Advocates wrote in the letter. “The charges detail that workers did not receive sufficient time to even timely break their day-long Ramadan fasts; workers also reported being told by Amazon management to quit when they requested time off for Eid al-Fitr, one of the most important Muslim holidays.”

All three women also participated in a rally in December to protest conditions at Amazon’s Shakopee, Minnesota, facility. Afterward, they said, they were treated differently by their managers.

“After the protest, I began to be treated differently, including receiving write-ups for low rates ― even though, in the past, I had occasionally posted lower rates but had not received write-ups for them,” one of the women, identified as Ms. C, said, according to Muslim Advocates.