Three alleged members of a West Seattle street gang pleaded not guilty today to charges stemming from a case in which prosecutors say a dozen women and girls were forced to commit sex acts last year.

Three alleged members of a West Seattle street gang pleaded not guilty today to charges stemming from a case in which prosecutors say a dozen women and girls were forced to commit sex acts last year.

Defendants pleading not guilty in King County Superior Court today were Shawn S. Clark, 20 and Gerald Jackson, 21, charged with promoting prostitution and Mycah Johnson, 19, charged with promoting commercial sex abuse of a minor.

Following a brief outburst, a woman believed related to one of the defendants was escorted from the courtroom after she attempted to prevent a photographer from taking pictures of the proceedings.

Prosecutors say the men were part of a gang called the Westside Street Mobb, which forced 12 women and girls to perform sex acts for money, then took the money they had collected from customers.

Three other men have been charged in the case, including two who have plead not guilty and are scheduled to go on trail in May. DeShawn Clark, 18, and Thomas L. Foster, 19, are charged with promoting prostitution; Clark is additionally charged with second-degree human trafficking.

A sixth defendant, Desmond Manago, 20, is scheduled to be arraigned Thursday.

In court documents, prosecutors allege that the charges stem from a November sting operation in which members of the Seattle police vice unit arrested a 19-year-old woman who had advertised sex services on Craigslist. The woman said Clark forced her to commit sex acts for money, beat her and took her earnings, charging papers said.

Prosecutors said the woman led police to other women who were forced into prostitution.

Jack Broom: 206-464-2222 or jbroom@seattletimes.com. Seattle Times staff reporter Sharon Pian Chan contributed to this report.