More than 100 Uber and Lyft drivers have reportedly sexually assaulted their passengers, according to a report by CNN.

After analyzing police reports, federal court records and county court databases across the U.S., the news site found that over the last four years, at least 103 Uber drivers and 18 Lyft drivers have allegedly raped, forcibly touched or kidnapped passengers, among other crimes.

Uber and Lyft give millions of rides per day and ride-hailing has taken the world by storm as more people sign up to use the services. As they've grown, the companies have also come under fire amid reports of drivers committing crimes with news of alleged assaults popping up several times a month. Both Uber and Lyft have declined to release any data on such allegations.

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A handful of states, including California, Colorado, Massachusetts and Texas, have previously launched investigations into Uber and Lyft, alleging they routinely fail to screen drivers adequately and have hired drivers with criminal histories.

Uber has acknowledged the problem and says it's working hard to make its platform safer. The company launched several new safety features earlier this month, including an in-app emergency 911 button and tougher driver screenings that require annual background checks. It also stopped giving drivers a log of passengers' pick-up and drop-off addresses.

Uber also has built a global team of former law enforcement officials to handle requests from police on active investigations. The company named former U.S. Secretary of Homeland Security Jeh Johnson as chairman of its Safety Advisory Board.

"These stories are horrific and our hearts go out to the victims," an Uber spokeswoman said in an email. "We worked with CNN to understand their findings and determined that Uber did 2.4 billion trips in the U.S. in that same period. But even one incident on our platform is too many which is why safety is Uber's top priority for 2018 and beyond."

Lyft didn't return a request for comment on the CNN report.

Both Uber and Lyft use a third-party screening company called Checkr to conduct their background checks. Checkr does a seven-year criminal history check at a series of national, state and local databases. It also checks the National Sex Offender Public Website and other databases. However, some security experts say these checks aren't as thorough as state and FBI fingerprint background checks, which both companies have long refused to do.

At least three lawsuits have been filed against Uber over allegations of sexual assault. Uber settled a 2015 suit filed by two "Jane Does." Another lawsuit was brought in 2015 by a woman who was raped by an Uber driver in India. Uber also settled that suit, but the issue was reignited last year after it was alleged that Uber executives obtained and mishandled her medical records.

A new lawsuit against Uber was filed in California's U.S. District Court for the Northern District in November. This suit involves nine women who say their Uber drivers sexually assaulted them in separate incidents, according to court documents. The alleged assaults took place across the U.S., including in Pennsylvania, Florida, California, Michigan, New York, New Jersey and Iowa.

Many of the alleged incidents involved young women who were intoxicated, hailed an Uber ride and then fell asleep in the backseat of the car. For example, one woman, who lives in Los Angeles, alleges an Uber driver assaulted her while she was asleep in his car and then took her home and raped her, according to court documents.

Lawyers for the women say Uber's background checks are inadequate and the company has misrepresented how safe the service actually is. The lawsuit is asking the court to force Uber to change the way it screens drivers and be more transparent about what it knows in regard to alleged sexual harassment and assaults by drivers.

Of the 103 Uber drivers that CNN identified, 31 have been convicted of the crimes they allegedly committed against passengers. Of the 18 Lyft drivers, four have been convicted. Dozens more drivers have criminal and civil cases that are pending, according to CNN.