A former Los Angeles elementary school teacher who taught for more than 35 years has been arrested on accusations he sexually abused 20 students and one adult. 

Police say Robert Pimentel has been charged with 15 felonies, and he is expected to be charged with misdemeanors for the remaining incidents at George De La Torre Jr. Elementary in the Wilmington area of Los Angeles.

Pimentel, 57, left his fourth-grade teaching position in March at the onset of the investigation, which was first reported by MyFoxLA.com. He had taught in the district since 1974. 

An 11-year-old told MyFoxLA.com Pimentel would try to "rub up against" her classmates during school. The investigation into Pimentel was launched after several students reported the abuse to their parents.

When officials learned of the allegations earlier this year they immediately removed Pimentel from campus and parents and state accreditation authorities were informed, school district spokesman Daryl Strickland said. Parents and guardians will be told of the arrest by letter and phone, he said.

There have been a number of high-profile incidents of Los Angeles teachers accused of sexually abusing students. 

More than 225 parents and students are involved in various claims for damages against the district after Miramonte Elementary School teacher Mark Berndt was arrested a year ago and pleaded not guilty to 23 counts of lewd conduct.

Berndt is accused of feeding his students his semen on cookies and photographing them in classroom "tasting games."

In December, a jury ordered the district to pay a boy molested by an elementary school teacher $6.9 million -- among the largest awards in the history of the school system.

The jury found the district liable for the repeated molestation of the 10-year-old student in 2008 and 2009 by teacher Forrest Stobbe at Queen Anne Elementary School in the city's mid-Wilshire district.