AUSTIN, Texas (AP) — Texas regulators say an operation targeting illegal sales to underage drinkers has found about 91 percent of the locations obeyed beverage laws.

The Texas Alcoholic Beverage Commission on Monday announced results of the sting using volunteers under age 21, the legal drinking age in Texas.

The TABC in August announced plans to concentrate this fall on communities with major colleges and universities as classes began.

The agency conducted 933 operations. Underage buyers, accompanied by TABC agents, tried to purchase liquor and presented valid identification.

Agency officials say 81 retailers were issued a notice of administrative violation, facing possible fines or suspension of liquor permits. Employees who sold the alcohol could also face charges.

A similar spring break sting targeted 930 Texas retailers, resulting in 92 TABC violations.