Unknown hackers gained access to sensitive information, including Social Security numbers, of more than 130,000 current and former U.S. sailors, the U.S. Navy said Wednesday. The information was stolen from a laptop used by a Hewlett Packard Enterprise Services employee working on a U.S. Navy contract.

The Navy said in a statement Hewlett Packard informed authorities of the breach Oct. 27 and the affected sailors will be notified in the coming weeks. Since then, the Naval Criminal Investigative Service (NCIS) has continued the investigation, and so far found that information of 134,386 current and former sailors' was accessed.

"The Navy takes this incident extremely seriously — this is a matter of trust for our sailors," Chief of Naval Personnel Vice Adm. Robert Burke said in the statement, cited by Reuters.

Burke said the investigation was in its early stage and authorities "are working quickly to identify and take care of those affected by this breach."

The Navy reportedly said Wednesday that "at this stage of the investigation, there is no evidence to suggest misuse of the information that was compromised."

In 2013, the U.S. blamed Iran for a series of cyber attacks launched at Navy computers. U.S. officials claimed at the time the attacks were launched by the Iranian government or a hacking group that was employed by the government, and added no valuable information was stolen. However, Iran denied the allegations and called them politically motivated.