By Feras Bosalum
BENGHAZI Libya (Reuters) - A U.N. special envoy visited Libya's elected parliament in the eastern town of Tobruk on Monday in a show of support against a rival assembly set up by armed groups that seized the capital, Tripoli, last month.
Bernardino Leon arrived in Tobruk to discuss with lawmakers a political solution to the crisis arising from two competing parliaments and governments.
U.N. Secretary-General Ban Ki-moon described Libya's slide into political uncertainty and hostilities to the U.N. Security Council as "deeply alarming."
"The specter of rival claims of legislative and executive authorities can only deepen the existing political crisis and undermine the country's national unity," Ban wrote in a report to the Security Council on the U.N. political mission in Libya.
The House of Representatives and senior government officials moved their headquarters east to near the Egyptian border when Tripoli fell to an alliance of armed factions from the western city of Misrata in August after a long battle with rival groups.
The House was elected in June and its previous name, the General National Congress, was scrapped because many Libyans associated it with political chaos. But the alliance controlling Tripoli and some former lawmakers have reinstated the GNC.
"The legitimacy lies only with the House of Representatives, which won legitimate elections," said Samir Ghattas, spokesman for the U.N. Mission in Libya. "We want a political solution and are against the use of violence."
Libya's persistent fighting and lawlessness have prompted most foreign countries and the United Nations to close their diplomatic missions in the country. Ban said the world body was reviewing its presence in the country.
"Given the rapidly evolving situation, it is essential to ensure that our presence and engagement in Libya is appropriate to the context and that we are well equipped to support the Libyan authorities in confronting current and anticipated challenges," Ban wrote.
The conflict is part of a wider struggle among former rebels who helped topple Muammar Gaddafi in 2011 but have now turned their weapons on each other in their fight to take power and control the country's vast oil reserves.
Western powers worry that a chaotic Libya could flood Europe with migrants and become a safe haven for militant Islamists.
The volatile situation in Tripoli has been exacerbated by separate clashes in the eastern port city of Benghazi, where Khalifa Haftar, a renegade general from the Libyan army, has launched war on Islamist militants.
Haftar's units, allied to regular special forces, have lost several army camps to Islamists who have been trying for days to seize Benghazi's airport and air base.
Ban said there had been no independent verification of the identity of fighter jets that carried out mysterious air strikes against Libyan Islamist militants last month. U.S. officials suggested Egypt and the United Arab Emirates were responsible.
(Reporting by Feras Bosalum, Ulf Laessing and Michelle Nichols; Editing by Tom Heneghan and Jonathan Oatis)