“We think there is a bias against the Muslim institutions,” said Kevin Vodak, the lawyer for CAIR-Chicago. He noted that the board rejected the Irshad proposal without explanation, which is highly unusual, and that last fall the county took up an amendment to prohibit any new religious institutions in residential areas. “Most of the new proposals are from Muslims,” Mr. Vodak said.

A measure that could streamline the process of establishing places of worship and other forms of assembly in unincorporated DuPage County is heading to the zoning panel that recently has taken up two zoning proposals from Islamic groups.