Upset with a perceived lack of opportunities for Richmond, Va.’s minority contractors, the executive director of the NAACP’s Virginia state conference has threatened “direct action” against current and planned city construction projects.

King Salim Khalfani alleges that only 6% of city contracts have minority involvement in planning or construction, reported the Richmond Times-Dispatch. Unless that figure is improved, Khalfani said, the NAACP will disrupt various projects. One tactic would be parking unmarked dump trucks at construction sites to block access.

The organization is focusing on projects that are publicly funded or receive government-backed financing.

Potential targets include the Richmond Redevelopment and Housing Authority’s planned Dove Street revitalization project, slated to add more than 300 mixed-income housing units; the $18.5-million renovation of a 1920s-era downtown hotel into a mixed-used residential and commercial complex; and two hotels proposed for a historically African-American neighborhood.

The NAACP also is contemplating legal action to force project owners to increase minority involvement and open more job opportunities to low-income residents. The mayor’s office said the city already has plans under way to increase minority participation, but declined further comment.

Minority participation in municipal contracts has long been a contentious issue in Richmond, where African-Americans make up more than 50% of the population. In 1989, the U.S. Supreme Court ruled in City of Richmond v. J.A. Croson Co. that the city’s minority set-aside program for construction contracts was unconstitutional. The Supreme Court found the Richmond City Council had failed to justify the rationale for awarding 30% of contracts to minority businesses.

This article originally appeared on ENR.com.