BATON ROUGE, La. (AP) _ As state senators quietly debated whether to override Gov. Buddy Roemer's veto of a strict anti-abortion bill Saturday, hundreds of demonstrators shouted their stands as they broiled in the sun outside.

The Senate sustained Roemer's veto of what would have been the nation's toughest state abortion law. The vote was 23 in favor of the override - three short of the two-thirds majority needed - and 16 against.

Before senators cast their ballots, the parking lot at the skyscraper Capitol was jammed with about 1,500 people as temperatures inched into the 90s.

State troopers limited access to the building, allowing almost 200 spectators in the Senate chamber, with another 500 in the rotunda separating the House and Senate chambers. Several hundred more gathered on the Capitol steps or under shade trees on the grounds.

Most of the crowd was in favor of the strict anti-abortion bill, which would send abortionists to jail for up to 10 years.

Anti-abortionists' cries of ''override, override'' pervaded the thick stone walls of the Senate chamber, in which every chair was filled and spectators lined up along the walls.

Another anti-abortion rally was held on the Capitol lawn, while about 100 pro-choice demonstrators stood on the steps above them, shouting ''sustain that veto'' and ''church and state - separate.''

After the Senate voted to sustain, one pro-choice supporter yelled ''all right'' and was told by security officers to be quiet.

Then she ran from the chamber, screaming ''I'm out of here.''

As other viewers quietly filed out of the gallery, abortion rights supporters waved purple flowers and ribbons in the rotunda, shouting: ''We won.''

Anti-abortionists countered with ''We will win. We will win.''

The Senate was to vote against Sunday on the override measure.