Several groups took to Los Angeles Street in front of the Federal Building downtown, demanding an end to war.
About 150 people gathered and prayed first at Our Lady Queen of Angeles La Placita Catholic Church, and then went on a march through downtown Los Angeles.
Another protest gathered on the Westside in front of the Federal Building in Westwood.
A group called the Interfaith Communities United for Justice and Peace called for the withdrawal of all troops and private contractors from both Iraq and Afghanistan. The group wants an end to drone attacks and to redirect all funding for wars to jobs, education, health care and housing. Protesters say the money should be spent at home during the country's economic downturn.
"Chaos is going on in this country, and it's because of the confusion and the anger on the parts of the people who don't understand why we're suffering in this country and causing suffering in other countries," said actor and activist Mike Farrell.
Farrell also said the resolution can be found in the country's $700 billion defense budget.
It came less than a month after the September 11 attacks.
In a planned act of civil disobedience, 15 people from Interfaith Communities were arrested downtown. The arrests were coordinated with police. Those arrested were expected to be released later Friday.