More than 1,000 San Francisco Unified School District students walked out of class and were heading to City Hall on Thursday morning in protest of president-elect Donald Trump, district officials said.

The district announced the walkout just after 9:30 a.m. on Twitter.

The students were marching on Market Street as well.

District officials said in a statement that the walkout was not organized by school leaders, though they are working with police to monitor the protest.

“We recognize our students’ right to free speech and understand their need to use it,” district officials said. “The walkout this morning was not authorized by SFUSD staff. Per our standard protocol, we will be notifying families regarding their unexcused absence through our attendance system.

“Because this walkout consists of over 1000 students, SFUSD administrators and leaders will be working with SFPD to monitor the situation and ensure student safety.”

San Francisco Municipal Railway spokesperson Paul Rose said Muni service along Market Street was re-routed to nearby Mission Street as aresult of the protest.

Drivers were told to expect traffic delays downtown due to the protest.

Estimated that over 1,000 students from across #SF walked out of school and are heading to Civic Center in peaceful protest.

— SF public schools (@SFUnified) November 10, 2016

@gwhs_official protesters on Geary. Go Eagles! pic.twitter.com/9789gJfbHC

— planetpj (@planet_pj) November 10, 2016

The aftermath after 1,000 #SF high school students arrived at City Hall to protest #Trump pic.twitter.com/93v8UU9q23

— Jessica Christian (@jachristian) November 10, 2016

1000 angry teens @ #SF CIty Hall w pride flags & signs saying “si se puede” & “No hate”. Their parents/teachers brought them to #protest <3

— Luke Fuller (@lsefuller) November 10, 2016