Six Libyan families sued the putschist commander Khalifa Haftar and the United Arab Emirates government in a federal U.S. court Monday for their alleged roles in committing war crimes in Libya.

In a lawsuit filed in the Federal District Court of the District of Columbia, the families -- whose relatives were murdered, injured or faced attempted killings -- are seeking $1 billion in damages, according to a news release by the plaintiffs' attorneys, Martin F. McMahon & Associates.

"By filing the lawsuit in Washington, the plaintiffs will bring to light the serious human rights abuses, extrajudicial killings and torture which the defendants have engaged in with absolute impunity and without fear of accountability," said the release.

Haftar is "not just a war criminal, but also a U.S. citizen with assets and family members" in the U.S. and "he can and will be held accountable for his illegal and barbaric acts," said McMahon in the release.

Forces loyal to Haftar launched a campaign in early April last year to topple the Tripoli-based Libyan government recognized by the U.N.

Clashes between the two sides since then have left more than 1,000 people dead and about 5,500 wounded, according to the World Health Organization.

Libya has remained beset by turmoil since 2011 when long-time ruler Muammar Gaddafi was ousted and killed in a bloody NATO-backed uprising after four decades in power.

The oil-rich country has since seen the emergence of two rival seats of power: one in eastern Libya, with which Haftar is affiliated, and the Tripoli-based Government of National Accord (GNA), which enjoys U.N. recognition.