SAN DIEGO -- More than 700 homeless veterans and their families will receive free shelter and social services Friday during the start of the three-day "Stand Down for Homeless Veterans."

The event, now in its 20th year, is run by Veterans Village of San Diego and has been replicated in more than 200 cities throughout the country.

Hundreds of volunteers will provide a range of services from shelter, food, clothing, showers and haircuts to legal assistance, mental health and substance abuse counseling and help with veterans benefits and job placement.

More than 130 medical staff volunteers will also be on hand over the course of the weekend to provide treatment for veterans.

Participants live in tents erected by active-duty military volunteers.

"Stand Down" runs through Sunday at San Diego High School's upper athletic fields in downtown.