Facebook Inc could be subjected to at least two more state probes in the United States on the alleged mishandling of user data, Bloomberg on Thursday.

The report, which cited people familiar with the matter, said Pennsylvania Attorney General Josh Shapiro and his Illinois counterpart Kwame Raoul have joined forces with Connecticut to focus on investigating existing allegations.

The state probes are coalescing into two main groups, the report said. The states of New York, New Jersey and Massachusetts are also probing the social media giant and are seeking to uncover any potential unknown violations.

The Illinois attorney general's office declined to comment on Bloomberg's report when contacted by Reuters, while the office of the attorney general of Pennsylvania did not immediately respond to a request for comment.

Facebook told Reuters in an emailed statement it was having "productive conversations" with attorneys general from a number of states.

"Many officials have approached us in a constructive manner, focused on solutions that ensure all companies are protecting people's information, and we look forward to continuing to work with them," Facebook's vice president of state and local public policy, Will Castleberry, said.

Facebook and other tech giants have been under pressure for over a year after it was revealed that British consultancy Cambridge Analytical acquired data on millions of US users to target election advertising. That led to heads of several tech companies testifying before Congress last year.