By Brad Brooks, Phil Stewart, Idrees Ali and Dietrich Knauth LOS ANGELES (Reuters) -Hundreds of U.S. Marines arrived in the Los Angeles area on Tuesday under orders from President Donald Trump, as the city's mayor declared a curfew for parts of the downtown area and police arrested 197 people in a fifth day of street protests.

A cloud of uncertainty is hanging over Los Angeles, where questions remain over the role that Marines and National Guard troops will play after being called in by President Donald Trump amid protests over immigration raids in the city.

White House "border czar" Tom Homan said that protests in Los Angeles are complicating immigration raids, making them more "difficult" and more "dangerous."

From Seattle and Austin to Chicago and Washington, D.C., marchers have chanted slogans, carried signs against ICE and snarled traffic through downtown avenues and outside federal offices.

Hundreds of protesters marched through downtown Milwaukee to decry the Trump administration's immigration crackdown.

President Donald Trump’s deployment of military troops to California is forcing Democrats back onto politically perilous turf, as they look for ways to condemn Trump’s actions without being drawn into a broad debate over immigration or tying themselves to the chaotic scenes emerging from Los Angeles.

Protests have continued in the Los Angeles area since Immigration and Customs Enforcement conducted mass arrests in the area Friday.

The Mexican national soccer team will change hotels in Los Angeles ahead of their Gold Cup match on Saturday because of safety concerns amid the protests against immigration raids in the city.