TRIPOLI, Libya (AP) — Libya’s parliament swore in an Islamist-backed businessman as the country’s new interim prime minister Sunday after a disputed vote and a walkout by secular lawmakers, the latest political turmoil in a country where powerful militias hold sway years after its civil war.

Despite the protest, the interim parliament named 42-year-old businessman Ahmed Matiq as prime minister in a rushed televised session headed by the second deputy of parliament, Saleh al-Makhzoum, a member of the Muslim Brotherhood’s Justice and Construction Party. But with lawmakers promising to challenge the decision, it remains unclear who will be prime minister in Libya, which is still plagued by insecurity following the ouster and the killing of longtime dictator Moammar Gadhafi in an eight-month civil war.