SAN FRANCISCO (AP) — Thousands of abortion opponents gathered for an annual demonstration on Saturday, the 38th anniversary of the Roe v. Wade Supreme Court decision that legalized abortion.

Demonstrators packed Justin Herman Plaza in downtown San Francisco before marching along the Embarcadero in a line that Eva Muntean, co-founder of the San Francisco group Walk for Life West Coast, said stretched for more than a mile. The event last year was attended by as many as 35,000 people, the group estimated.

READ MORE: Suspect Remains Hospitalized In Wrong-Way Crash On I-80 That Killed 4

The police department did not provide an estimate on the crowd size. Officers were on hand to monitor the march, according to police spokesman Albie Esparza. As of mid-afternoon, no disruptions were reported.

Some demonstrators carried signs that read, “Women deserve better than abortion” and “Defend Life.”

“Everybody suffers in the wake of abortion,” the Rev. Brian Walker of the Pro-Life Action Ministries, which has offices in Minnesota and Florida, told the crowd. Walker said his marriage was in “shambles” after his wife had an abortion years ago.

READ MORE: 'Your Life Does Not End Because You Have A Diagnosis': Shantel Smith Opens Up About Her Battle With Multiple Sclerosis Before 'Survivor'

A small group of abortion-rights advocates, including anti-war activist Cindy Sheehan, held a counterdemonstration across from the plaza. Christine Sampson, 38, had a sign that read, “Protect Women, Protect Choice.”

The San Francisco resident said she attended in part because she thinks Roe v. Wade is under attack. “It does seem that the tide is turning against a women’s right to choose,” she said.

Protests are planned this weekend throughout the nation. Anti-abortion activists will participate in an annual March for Life rally Monday in Washington, D.C.

MORE NEWS: Body Found At Bottom Of Embankment In Yuba County; Suspicious Death Investigation Underway

(Copyright 2011 by The Associated Press.  All Rights Reserved.)