Seattle mayor calls Trump's threat to send in military 'illegal'

But Mayor Jenny Durkan, speaking at an afternoon press conference, did not say how or when authorities would remove the roughly 500 demonstrators who have established a makeshift encampment behind barricades in the Capitol Hill district.

"It is unconstitutional and illegal to send the military into Seattle," said Durkan, a first-term Democrat. "There is no imminent threat of an invasion of Seattle."

Activists have occupied the area since police on Monday night moved barricades blocking the streets and abandoned their East Precinct station in a move city officials say was aimed at reducing tensions.

Protesters used the police barricades to section off the area, calling it the "Capitol Hill Autonomous Zone."