[UPDATES BELOW] Anti-Trump activists have gathered to block security checkpoints to the inaugural parade this morning, the first major action in a weekend of protest and resistance against the new administration. Protesters clashed with police at several security checkpoints, chaining themselves to fences and linking arms to block the entrance.

Security has been tight, and crowds of both Trump supporters and protesters began lining up early this morning.

These protests have been coordinated by the volunteer-run group DisruptJ20, who have been planning to wreak havoc and cause disruptions in the proceedings.

Each checkpoint action was organized by a local group or coalition dedicated to a specific political cause—there was a Movement for Black Lives checkpoint, a Standing up for Racial Justice checkpoint, a Trade Justice, and a Climate Justice checkpoint, as well as a “Future is Feminist” checkpoint and a “Qockblockade” Brigade, which is highlighting LGBTQ issues. The diversity of causes was mirrored by the diversity of participants, many of whom began gathering in solidarity against the new regime around 5 a.m. They have also joined up with other protest groups—this video shows a “Pro Palestine protest [that] just met up with D.C. Union protest, linked arms blocking entrance at 1st and D.”

The action has caused some Trump supporters to seek out police, and just after 7 p.m. protesters were seen being physically removed from checkpoint areas. Videos show police shoving and spraying protesters.

Some protesters have also been chaining themselves to the checkpoints:

A permitted DisruptJ20 march is planned for today at noon starting at Columbus Circle and heading down McPherson Square, where protesters will meet up with another permitted march run by Occupy Inauguration. According to DisruptJ20 organizers, McPherson Square will be set up for a rally, with tents, toilets, and a stage.

Tomorrow’s Women’s March on Washington will be by far the largest anywhere in the country, with well more than 200,000 expected to attend.

Update, 8:30 a.m.: Protesters have shut down the security checkpoint at John Marshall Park.

Update, 10:53 a.m.: Protests are continuing, and some inauguration attendees aren’t really too pleased with it. At least one has suggested taking a page out of The Mighty Ducks playbook.

Protesters are moving on from the John Marshall Park security checkpoint, with a brass band in tow:

Update 11:09 a.m.: Tear gas, smashed bus stops, riot cops and running protesters.

Update 11:50 a.m.: Inauguration attendees are making their way in, as protests continue elsewhere and police confiscate apples.

Update 12:15 p.m.: As Trump is sworn in, demonstrators stage a sit-in. Also Vermin Supreme is here.

Reporting from Rachel Kurzius, Rachel Sadon, Scott Heins, and Emma Whitford