PITTSBURGH — Two protest groups are asking for an emergency hearing into allegations that Pittsburgh police are harassing them in the run-up to the opening of the Group of 20 global economic summit.

Seeds of Peace and Three Rivers Climate Convergence say in a lawsuit filed in Pittsburgh on Monday that police are discouraging their rights to free speech.

The groups say a Seeds of Peace bus was illegally searched and seized, and its members have been detained by police without cause.

The groups are planning to demonstrate against the G-20 summit when it convenes in Pittsburgh on Thursday. The summit is a gathering of nearly two dozen world leaders, whose countries control about 90 percent of the world's wealth.