(Reuters) – U.N. Secretary-General Ban Ki-moon has named former Deputy U.S. Secretary of Homeland Security Jane Holl Lute as his special adviser to help with the relocation of a group of Iranian dissidents in Iraq to new countries, the U.N. said on Sunday.

“Ms. Holl Lute will work with a wide range of stakeholders, in particular Member States, with a view to facilitating the relocation of residents of Camp Hurriya outside of Iraq,” the U.N. press office said in a statement.

The appointment of Holl Lute, who was a senior U.N. official from 2003 to 2009, comes after a series of attacks on the dissident Mujahadin-e-Khalq (MEK) group in Iraq.

More than 50 people were killed at Camp Ashraf, the MEK’s previous camp in Iraq, in September in an attack the United Nations described as “an atrocious crime” and which drew condemnation from the United States and Britain. Assailants took time to conduct execution-style killings and plant bombs.

Iraqi authorities have repeatedly denied involvement in the September attack, during which seven camp residents vanished. MEK says they were taken hostage by Iraqi forces and flown to Amara province to be extradited to Iran. A U.N. expert group has urged Baghdad to swiftly investigate the disappearances.

The MEK, which has accused Iraqi security forces of being behind the attack, is no longer welcome in Iraq under the Shi’ite Muslim-led government that came to power after U.S.-led forces toppled former Iraqi dictator Saddam Hussein in 2003.

The last residents moved out of Ashraf to a new base, Camp Hurriya [Camp Liberty], in September. Camp Ashraf had housed around 100 MEK members at the time of the September attack.

There was also a deadly rocket attack on Camp Hurriya on December 26, which the MEK says killed four residents and injured around 70 more. The MEK blames the Iraqi and Iranian governments for the December 26 assault.