The roll call showed almost 45,000 teachers on strike across the country yesterday with San Francisco the latest big city facing a delay in the opening of the fall term.

The nearly 300 public schools in Detroit remained shut down for a second day as 12,000 teachers remained off the job and San Francisco's 3,600 teachers organized picket lines to prevent classes from starting today.

The San Francisco teachers voted 1,306 to 550 on Monday not to return to work until they get a new contract and an agreement from school officials to rescind layoffs.

A survey showed 44,960 teachers were off the job at schools attended by 865,900 students in 13 states. Among those, 20,300 teachers are on strike in 25 Michigan school districts, disrupting classes for 375,000 students.

Other strikes were affecting scattered school districts in Alaska, Illinois, Indiana, Louisiana, New Jersey, Ohio, Oregon, Pennsylvania, Rhode Island, Washington and Alabama.

The Detroit teachers voted to strike after rejecting an offer of a 25 percent pay increase over three years, which did not include a provision for a cost-of-living increase.

In Los Angeles, the first day of classes was relatively smooth after a last-minute contract offer by the school board averted a partial sickout by the United Teachers of Los Angeles.