Law enforcement officials are stepping up efforts to draw out tips from neighborhood residents with information on crimes, with launch of a multi-platform ad campaign that says the program guarantees tipsters’ anonymity.

Roughly 4,000 tips have come in via text message since the “Text a Tip” program was first launched in 2007, according to city officials. The program is focused on youth, who tend to text more than talk on the phone.

The program enables community members to anonymously text the word ‘TIP’ to CRIME (27463).

The ads, put together with the help of advertising firm Hill Holiday, will be placed in Fenway Park, at MBTA stations, in city shelters, and on social networking sites such as Twitter and Facebook.

The ads promote the anonymity of the program through pixilated images of people. “Boston is filled with heroes. Good luck finding them,” one ad says.

Another one says, “Like other superheroes, you’ll never reveal your identity.”

The campaign will be seen at 50 bus shelters, 200 MBTA cars, a dedicated page on BPDnews.com, and for two days on Boston.com. The Fenway Jumbotron will have a public service announcement about the program, and the police department will distribute 5,000 brochures.

“Recent senseless acts of violence try our resolve,” Mayor Thomas Menino said at a Friday press conference announcing the ad campaign. “But we need to stay strong in our will to promote peace and make our neighborhoods even safer.”

Menino and others at the press conference, held at Boston Police headquarters, said the ads were in the planning stages for several months, and not a reaction to the July 4th bloodshed.

Other partners in the re-launched campaign include AT&T, outdoor advertising specialist JCDecaux North America, MBTA, the Boston Red Sox, and the Boston Police Foundation. AT&T donated $85,000 to the effort, and JCDecaux donated the bus shelters.

Mike Sheehan, CEO of Hill Holiday, said the company was “being a good corporate citizen” by helping out with the ads. He said that after about 4,000 tips, no one has been revealed.

“And that is the message we are communicating in this campaign,” he said.