However Kevin Donahue, DC's Deputy Mayor for Public Safety and Justice, said that the situation was not an active shooter.
Although no shots were fired, hundreds of people ran from the area, knocking down metal police barricades and running into stores, fearing a gunman had opened fire on the revellers.
A fire department spokesman said emergency medical personnel tended to people who were injured, but could not immediately provide any additional information about the number of victims or the extent of their injuries.
A police officer stands behind crime scene tape, Saturday, June 8, 2019, at Dupont Circle in Washington.
But police did not find any evidence of shots fired, Rivera said.
Police said some of the people who ran sustained minor injuries and others transported to hospitals. A man pulled out a B.B. gun on someone else, cops said in a WTOP report.
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"You just heard people scream and they just started booking it", Tom Roussey said.
The police report says officers made contact with Duffy, whom the report lists as Suspect 1, due to her significant other being arrested.
Elizabeth Hernandez, 19, told AP that she heard a "pop, pop" during the parade.
The president, Ashley Smith of Capital Pride Alliance, said he saw people running toward him from Dunpont Circle.
"We can not allow this incident, until we know all the facts of it... to ruin the pride celebration going on this weekend", said Ashley Smith, president of Capital Pride Alliance, which organizes the annual event.
"We're very thinking about desirous to be definite we proceed to have a colossal tournament for the comfort of the weekend".
Guillermo Rivera, a commander with the Metropolitan Police Department, said the department had an "adequate amount of resources on the ground, which is why we were able to respond so quickly".