(CNN) -- The leader of a Tunisian militant Islamist group was arrested in Libya on Monday, state media reported, citing a security source.
Libyan and American forces captured the militant leader, Tunisie Agence Presse reported. But the United States denied any involvement in the reported arrest of Seifallah Ben Hussein Mokni, who is also known as Abu Iyadh and heads Ansar al Sharia in Tunisia.
"Contrary to media reports, U.S. forces were not involved in any operations involving Ansar al Sharia leader Abu Iyadh today in Libya," Pentagon spokesman Rear Adm. John F. Kirby told CNN.
The Tunisian state media report accused Ansar al Sharia in Tunisia of ties to political assassinations in the country.
Ansar al Sharia in Tunisia denied through its official Twitter account that its leader had been arrested in Libya. The statement said that the "lying media" reported the "false rumors" to "play a dirty game" and influence its members to respond physically.
Ansar al Sharia in Libya, another Islamist militia group, was believed to be involved in the 2012 U.S. Consulate attack that killed four Americans in Benghazi, Libya.