The Iran-backed Shi’ite militia Kata’ib Hezbollah, which the U.S. State Department designates as a Foreign Terror Organization, is holding a dual Israeli-Russian citizen hostage in Iraq, the Israeli Prime Minister’s Office revealed on Wednesday.

Elizabeth Tsurkov, a Princeton University doctoral candidate and non-resident fellow at the Washington, D.C. think tank New Lines Institute for Strategy and Policy, has been missing for four months.

“Elizabeth Tsurkov is still alive, and we hold Iraq responsible for her safety and well-being,” said the PMO statement.

“The matter is being handled by the relevant parties in the State of Israel out of concern for Elizabeth Tsurkov’s security,” it added.

Tsurkov was visiting Iraq using her Russian passport to conduct academic research for her doctorate.

Kata’ib Hezbollah, or the Hezbollah Brigades, is an Iranian-sponsored Shi’ite militia that operates both in Iraq and Syria. As part of the Popular Mobilization Forces, the group has conducted countless attacks on U.S. and coalition forces in Iraq, leading Washington to designate it as a foreign terrorist organization in 2009.

America has accused Kata’ib Hezbollah of orchestrating a December 2019 rocket attack that killed a U.S. military contractor and wounded four soldiers.

Abu Mahdi al-Muhandis, Kata’ib Hezbollah’s secretary-general, was subsequently killed alongside IRGC Quds Force Commander Qassem Soleimani in a 2020 U.S. drone strike in Baghdad. The organization is currently headed by Ahmad al-Hamidawi, whom the State Department designated as a global terrorist in February 2020.