The parents of two Americans killed in the 2012 attack on the U.S. embassy in Benghazi, Libya, on Monday sued Hillary Clinton for allegedly contributing to their sons’ deaths by using a private email server during her tenure in the State Department.

Patricia Smith and Charles Woods allege that the deaths of their sons, Sean Smith and Tyrone Woods, were “directly and proximately caused, at a minimum” by Clinton’s communication of “confidential” email through the personal server. The suit, filed in U.S. District Court for the District of Columbia by the conservative Freedom Watch group, also accuses Clinton of “defamation and intentional and negligent infliction of emotional distress” against the families.

“Having used a secret private email server that we now know was used to communicate with Ambassador Christopher Stevens with confidential and classified government information, and which we also now know was likely hacked by hostile adversaries such as Iran, Russia, China and North Korea aligning with terrorist groups, it is clear that Hillary Clinton allegedly negligently and recklessly gave up the classified location of the plaintiffs’ sons, resulting in a deadly terrorist attack that took their lives,” Freedom Watch founder Larry Klayman said in a statement.

“Hillary Clinton told the plaintiffs that their sons were killed as the result of a video mocking the Islamic prophet Mohammed when she knew that they were murdered by Muslim terrorists,” Klayman continued. “When the families exposed her lies, she called them liars to protect her reputation and to further her own presidential ambitions.”

Clinton spokesman Nick Merrill told The New York Times in a statement Monday that no congressional investigations found her culpable for the attack.

“While no one can imagine the pain of the families of the brave Americans we lost at Benghazi, there have been nine different investigations into this attack and none found any evidence whatsoever of any wrongdoing on the part of Hillary Clinton,” he said.

Both Smith and Woods have publicly condemned Clinton’s handling of Benghazi during the 2016 campaign. Smith gave a speech at the Republican National Convention in July saying she “personally” faulted the former secretary of state for her son’s death.

Clinton testified before the House Benghazi Committee for eight hours last fall about her role in the attack and its aftermath. The committee filed a final report in June that produced no new evidence of wrongdoing on Clinton’s behalf.

In July, FBI Director James Comey concluded that her use of a private email server was “careless” but said that she should face no charges based on the lack of evidence of “intentional misconduct.”

Klayman, who filed the suit on the parents’ behalf, is known for his activist style of lawyering. He sued the Clintons repeatedly in the 1990s and filed a petition in 2014 to have President Barack Obama, who he insists is an “illegal alien,” deported from the U.S.

This post has been updated.