(CNN) -- Online classified service Craigslist's decision to censor its adult services section is a "good step but a continuing battle has to be fought," a leader in the fight against prostitution ads said on Sunday.
"I'm very pleased by this very solid and significant apparent step in the right direction," said Connecticut Attorney General Richard Blumenthal, who spearheaded a recent letter from 17 attorneys general urging Craigslist to discontinue its adult services section.
"I say apparent because we have received no definite or definitive word from Craigslist that the shutdown is permanent or complete," Blumenthal told CNN's Tom Foreman.
Blumenthal said he wants to broaden his fight against online prostitution ads but that "right now our focus is really on Craigslist."
"We're taking it one step at a time," he said. "We want to verify and confirm that Craigslist is in fact shutting down (its adult services section)."
The embattled website has been under fire for allegations that it promotes prostitution.
"These prostitution ads enable human trafficking and assaults on women," Blumenthal said Saturday. "They are flagrant and rampant. Craigslist has lacked the wherewithal or will to effectively screen them out."
The section that usually reads "adult services" on Craigslist was replaced Saturday by the word "censored."
It was not clear whether Craigslist removed the adult services and replaced them with the "censored" section, which had a link that was not active. But for users who accessed the account outside the United States, the adult services link was still active.
Craigslist representatives said on Saturday that they will release a statement at a later time.
"If it remains shut down it will be a model for other sites, we hope, because Craigslist is by far the biggest," said Blumenthal, who is running for the U.S. Senate in Connecticut as a Democrat.
He said that he would try to change federal laws to make it easier to prosecute sites like Craigslist.
"Craigslist says it cannot be held legally responsible for anything on its site," he said. "My belief is strongly ... that we need to change that."
In the August 24 letter to Craigslist CEO Jim Buckmaster and founder Craig Newmark, the attorneys general wrote: "The increasingly sharp public criticism of Craigslist's Adult Services section reflects a growing recognition that ads for prostitution -- including ads trafficking children -- are rampant on it."
Blumenthal said on Sunday that attorneys general from three more states have joined his campaign against Craigslist's adult services ads. Blumenthal didn't say which attorneys general joined the initial list of 17.
A Craigslist spokeswoman said at the time that the site agreed with at least some of the letter.
"We strongly support the attorneys general desire to end trafficking in children and women, through the internet or by any other means," said Susan MacTavish Best, who handles press inquiries for Craigslist.
"We hope to work closely with them, as we are with experts at nonprofits and in law enforcement, to prevent misuse of our site in facilitation of trafficking, and to combat such crimes wherever they appear, online or offline."
In their letter, the attorneys general highlighted an open letter, which appeared as a Washington Post ad, in which two girls said they were sold for sex on Craigslist.
When the ad came out, Buckmaster wrote a blog post in response that said, "Craigslist is anxious to know that the perpetrators in these girls' cases are behind bars."
The letter also highlighted a report in May by CNN's Amber Lyon, who posted a fake ad for a girl's services in the adult section. She received 15 calls soliciting sex in three hours.
Earlier this month, Lyon interviewed a woman named "Jessica" who sells sex on Craigslist. The woman said a Craigslist ad was "the fastest, quickest way you're for sure going to see somebody that day."
In a later blog post, Buckmaster said Craigslist implemented manual screening of adult services ads in May 2009. "Since that time, before being posted each individual ad is reviewed by an attorney," the post said.
He said the attorneys are trained to enforce Craigslist's posting guidelines, "which are stricter than those typically used by yellow pages, newspapers, or any other company that we are aware of."
Attorneys general from Arkansas, Connecticut, Idaho, Illinois, Iowa, Kansas, Maryland, Michigan, Mississippi, Missouri, New Hampshire, Ohio, Rhode Island, South Carolina, Tennessee, Texas and Virginia made the request a week after accused "Craigslist killer" Philip Markoff committed suicide in jail.
Markoff was charged with the April 2009 killing of Julissa Brisman. Boston Police said that Brisman, a model, advertised as a masseuse on Craigslist, and Markoff might have met her through the website.
In 2008, under pressure from state prosecutors, the website raised the fees for posting adult services ads. In 2009, it started donating portions of the money generated by adult ads to charity.
A CNN investigation of Craigslist's adult services section, which replaced "erotic services ads" two years ago, counted more than 7,000 ads in a single day. Many offered thinly veiled "services" for anything from $50 for a half-hour to $400 an hour.
CNN's Deborah Doft and Nicky Robertson contributed to this report.