WASHINGTON (AP) _ Vastly outnumbered but undeterred, several hundred foes of abortion prayed and sang hymns in a symbolic cemetery on the Washington Mall as hundreds of thousands of abortion rights activists marched past.

The mood inside the rust-red snow-fence bounding the ''Cemetery of the Innocents'' was one of quiet devotion Sunday as anti-abortion activists knelt amid 4,400 white wooden crosses and Stars of David, the number of unborn they said are aborted every day.

But emotions sometimes ran high at the edge of the fence, where several women held up enlarged color photographs of fetuses.

''I want people to see the other side. This is what they are choosing when they choose abortions,'' said Susan Brimmer, of Columbia, Md.

A number of abortion rights activists, as they marched past the cemetery to the Capitol, shouted ''Pro-Choice'' and other slogans, but moved away when blue-helmeted police asked them to avoid confrontation.

About 200 to 300 anti-abortion protesters gathered in pockets elsewhere on the parade route, displaying placards and trading taunts with the marchers. Police, some on horseback, kept the opposing groups apart.

In one pocket, about 50 college men and women stood at the base of Capitol Hill, holding up signs proclaiming that ''Abortion May be Legal, but it is not Moral,'' and urging the Supreme Court to ''Overturn Roe Vs. Wade,'' the decision which has legalized abortion since 1973.

One of those women, Michelle Sheahan, a student at Wellesley College, said she and 14 other abortion foes from her school rode down from Massachusetts on buses filled with anti-abortion activists.

Their message, she said, was that ''abortion exploits women,'' and that ''no one can decide for the unborn child.''

Ray Allen, head of the American Coalition for Life, which built the symbolic cemetery, said he wanted to ''communicate the message in a graphic way that abortion on demand kills children.''

Allen, who moved to Washington from Dallas three years ago to campaign against abortion, said he planned to return to Texas soon ''because the battle will be fought in the states.''

If the Supreme Court overturns Roe vs. Wade, states likely would have the authority to determine whether abortions would be legal within their borders.

Two women who said they underwent abortions told a news conference before the demonstration that they now oppose the operation.

''I will never forget the dream I had of my baby screaming as the doctor ripped that baby from my womb,'' said Nora Whitten, of Newark, Texas. ''Abortion is murder. Those involved in abortion seem to realize this, but try to hide their feelings because they are afraid to deal with the truth.''

Nola Jones, of Vacaville, Calif., said she regrets two abortions she had, in 1974 and 1977.

''I spent eight and one half years in denial, destroying myself from what is now called post-abortion syndrome,'' said Jones, executive director of an anti-abortion group called Victims of Choice.