TRIPOLI, July 18 (Xinhua) -- The United Nations Support Mission in Libya (UNSMIL) on Thursday expressed concern over the disappearance of Siham Sergewa, member of the eastern-based House of Representative, in the eastern city of Benghazi.

"UNSMIL is gravely concerned by and closely following up on media reports about the disappearance of Ms. Siham Sergewa and the injury of her husband. An elected House of Representatives member, Ms. Sergewa was reportedly taken by force last night from her residence in Benghazi," the Mission said.

UNSMIL called on Libyan authorities to investigate the attack on Sergewa's residence and to disclose her whereabouts and called for immediate release of the parliament member.

Libya has been suffering escalating violence and political instability since the fall of former leader Gaddafi's government in 2011.