via the Washington Times:
U.S. Park Police moved into McPherson Square on Sunday to force Occupy D.C. protesters to remove a wooden-frame structure that was to become a meeting house, and members of a SWAT team have entered the encampment.
Some of the Park Police officers are on horseback and are being joined by uniformed officers and a special weapons and tactics team from the Metropolitan Police Department.
Several arrests have been made. Protesters are sitting on the structure’s rafters and beams.