Protests that sprang up in Los Angeles over immigration enforcement raids and prompted President Donald Trump to mobilize National Guard troops and Marines have begun to spread across the country, with more planned into the weekend.

From Seattle and Austin to Chicago and Washington, D.C., marchers have chanted slogans, carried signs against the Immigration and Customs Enforcement agency and snarled traffic through downtown avenues and outside federal offices. While many have been peaceful, some have resulted in clashes with law enforcement as officers made arrests and used chemical irritants to disperse crowds.

Activists are planning more and even larger demonstrations in the coming days, with “No Kings” events across the country on Saturday to coincide with Trump’s planned military parade through Washington.

The Trump administration said it would continue its program of raids and deportations despite the protests.

“ICE will continue to enforce the law,” Homeland Security Secretary Kristi Noem posted Tuesday on social media.

About 150 protesters gathered outside the Federal Detention Center in Philadelphia on Tuesday afternoon and marched to ICE headquarters for speeches and then back to the detention center, according to Philadelphia police.

A group then walked though what police called major roads using bicycles to obstruct officers, prompting police to issue several orders for people to disperse. Police said demonstrators ignored the orders and things escalated when officers started arresting people.

Fifteen people were arrested, one on allegations of aggravated assault on police, and the rest for disorderly conduct, police said. Several officers used force during the arrests and their conduct will be reviewed, police said. Police didn’t say specifically what kind of force was used. Two officers had minor injuries and were treated at a hospital. Two females who were arrested reported minor injuries and were receiving medical attention, police said.

About 20 people remained peacefully gathered outside the detention center as of Tuesday night, police said. About 200 protesters gathered outside the San Francisco Immigration Court on Tuesday after activists said several arrests were made there.

That gathering came after protests on Sunday and Monday swelled to several thousand demonstrators and saw more than 150 arrests with outbreaks of violence that included vandalized buildings, and damaged cars, police vehicles and buses. Police said two officers suffered non-life threatening injuries.

“Individuals are always free to exercise their First Amendment rights in San Francisco, but violence, especially against SFPD officers, will never be tolerated,” San Francisco police posted on social media.

Police described Monday’s march as “overwhelmingly peaceful,” but said “two small groups broke off and committed vandalism and other criminal acts.” Several people were detained or arrested, police said.