Reuters) - A Washington-based journalist has sued St. Louis County and one of its police lieutenants, saying his rights were violated when he was arrested while covering protests over the killing of an unarmed black teenager by a white police officer in Ferguson, court papers showed.

Gerald Yingst, a reporter and producer with News2Share, also accuses police of defaming him by announcing his arrest on Twitter and saying he had refused a commander's order to clear the street, damaging his professional reputation.

A St. Louis Police Department spokesman referred enquires about the lawsuit to the St. Louis County counselor's office. No one answered calls placed there on Thursday evening.

Yingst was one of two people detained on Nov. 22 during one of the nightly protests outside the Ferguson police department as a grand jury mulled whether to charge Darren Wilson with the shooting death in August of 18-year-old Michael Brown.