Violent Protests Break Out During May Day Marches

May Day marches in Seattle ended with several violent outbreaks by demonstrators that left five officers injured and nine people arrested, according to police.

More exploding #MayDaySea pic.twitter.com/3RfRtyKD91

- Sam Levine (@samlevine) May 2, 2016Police reported being hit by rocks, batons and Molotov cocktails during Sunday clashes by black-clad protesters wearing masks and sunglasses.

Seattle Mayor Ed Murray released a statement commending police for their work in containing the protests while disavowing the acts of the demonstrators.

"It is unfortunate and deeply regrettable that in a city that goes to incredible lengths to respect First Amendment rights, there are some who disregard our values and engage in senseless acts of violence and property destruction," Murray said. "This city condemns any acts of physical violence against our police officers, and my thoughts are with the officers who were injured."

The protests had been trending for several hours on Twitter with the hashtag #MayDaySea.

Around the world, union members have traditionally marched on May 1 for workers' rights. In the United States, the annual events have become a rallying cry for immigrants and their supporters for better wages and fair work accommodations.

Seattle traditionally sees large, disruptive May Day gatherings. Last year, police arrested 16 people during demonstrations and in 2014 10 people were arrested.

In 2013, police arrested 18 people from a crowd that pelted them with rocks and bottles. Storefronts in downtown Seattle have also been smashed in previous protests, according to The Associated Press.