Nicholas Haysom, Special Representative of the United Nations Secretary-General for Somalia, has been asked by the Somalia government to leave the country.
"The decision came after the highest U.N. diplomat in Somalia violated the agency's standards and the international diplomatic norms by intervening the national sovereignty of Somalia," according to the statement published by the government-controlled media.
The statement gave no further details.
Human rights a concern
On Monday, the U.N. ambassador urged the Somali government to safeguard human rights.
In a letter, Haysom urged Somali authorities to "exercise its authority in conformance with the law and provide explanation about the atrocities committed in Baidoa last month and the detention of Mukhtar Robow."
Robow, a former al-Shabab leader, was arrest by the Somali government security forces last month. He also was excluded from elections in the South West Region of Somalia.
During his arrest, and the protests that followed, allegations came up that U.N.-supported regional police forces were involved in violence that left 15 civilians dead.
Analysts believe Haysom's earlier letter and the subsequent Somali government decision to expel him shows the relationship between the two sides has been unstable.
U.N. Secretary-General António Guterres appointed Haysom as Special Representative for Somalia and Head of the United Nations Assistance Mission in Somalia (UNSOM) in September 2018.
UN compound attack
On Tuesday, just hours before the Somali government's letter of expulsion was released to the media, two U.N. staff members and a contractor were injured after seven mortars landed inside the U.N. compound in the Somali capital, Mogadishu.
The staffers' nationalities were not immediately available, but the officials at the compound said none of the injuries were life-threatening.
"Today's indirect fire attack on the main U.N. compound in Mogadishu may amount to a violation of international humanitarian law, and I deplore this unwarranted act of aggression against our personnel," Haysom said in a statement issued in Mogadishu.
In a statement posted on a pro-al-Shabab website, the militant group has claimed responsibility for the attack.
"No political agenda can be served through violence that deliberately targets staff members of international organizations who are supporting the consolidation of peace and the strengthening of governing institutions in Somalia," Haysom added.