Those who grope others on the T have been warned that their inappropriate behavior will be exposed, as the MBTA announced its public awareness campaign to combat sexual harassment on public transportation yesterday.

Massachusetts Bay Transit Authority officials partnered with the Boston Area Rape Crisis Center for the campaign and said its launch coincides with Sexual Assault Awareness Month.

MBTA general manager Daniel Grabauskas said the transit authority wants a safe transit environment for everyone.

“If someone assaults or harasses you, we want you to tell us,” he said.

Grabauskas said 900 posters will be put up in T stations and on trains and buses to reach hundreds of thousands of commuters. MBTA employees will hand out fliers at the Park Street T station to encourage people to report any assaults they witness.

Victims can call the transit police hotline with descriptions of offenders, he said. The MBTA has also installed cameras on the T and in stations, and plans to put them in buses soon, Graubaskas said.

Acting Transit Police Chief Paul MacMillan said 44 sexual harassments or assaults on the MBTA were reported in 2007. Seventeen have been reported this year, five more than this time last year.

MacMillan said the campaign is supposed to last at least 90 days and will start up again in the fall when college students return to Boston. The awareness campaign will empower victims, as well as other other passengers, and “warn offenders they’re going to get caught,” he said.

He said many of those arrested for indecent assault and battery on the MBTA are “notoriously repeat offenders . . . the crime is more prevalent than [the numbers] being reported to the police.”

The campaign also encourages riders to speak up and confront the suspect, or take cell phone pictures of any suspects, MacMillan said.

“If you don’t feel comfortable doing that, get a good description and report it to the police,” he said.

MBTA police recently started a decoy operation, putting plainclothes officers on trains and buses. MacMillan said the officers made an arrest on the operation’s second night.

Gina Scaramella, Boston Area Rape Crisis Center executive director, said the campaign clarifies that the shame of sexual harassment belongs to the offender, not the victim.

“No one deserves to be sexually harassed, and groping and unwanted touching will not be tolerated,” she said.