Libya's Islamist militant group Ansar al-Sharia has said that it seized complete control of Benghazi late on Wednesday, declaring the city an "Islamic emirate," the group's representative said.
Ansar al-Sharia is blacklisted by the United States over its alleged role in an attack on the U.S. consulate in Benghazi, eastern Libya, Al Arabiya reported.
An official representative for the armed group told a local radio channel that Benghazi is now under its control.
"Benghazi has now become an Islamic emirate," said Mohammed al-Zahawi, the spokesman, to Radio Tawhid.
However, Khalifa Haftar, a retired, renegade former army general who earlier this year launched a self-declared campaign to clear the city of Islamist militants, denied the group's claims.
"The national Libyan army is in control of Benghazi and only withdrew from certain positions for tactical reasons," Haftar told Al Arabiya News Channel.
"The claim that Benghazi is under the control of militias is a lie," he said.
Ansar al-Sharia's declaration comes following two days of fighting in which Islamist fighters and allied militiamen overran an army base in the city.
Al Arabiya's correspondent in Libya reported that Islamist groups had seized the headquarters of the Libyan army's Special Forces in Benghazi late on Tuesday following heavy fighting.
Turkey's Anadolu news agency quoted Talal bin Harir, a Benghazi Shura Council member, as saying that the Islamists were in control of the army base.
Three years after the fall of Muammar Qaddafi, the OPEC nation has failed to control former rebel militias who refuse to disband and threaten the unity of the country.
The extent of recent hostilities has increased Western worries that Libya is sliding toward becoming a failed state and may once again go to war.
Several foreign states have withdrawn their citizens and diplomats from the state.