Brenda Kyeyune, including two Kenyans, one Afghan and three Somalis were killed in the explosion, according agencies, while eight other people, including a Ugandan were injured in the attack.
The attack on the Children’s agency has been widely condemned by the Somali government and international agencies.
Somalia police said the bomb was planted under a seat of the vehicle, according to agencies.
Somali’s President Hassan Sheikh Mohamud called it a direct attack on the future of the country.
“This attack is not just targeted at the United Nations, but in attacking UNICEF, al-Shabab has also attacked Somali children. It is an attack against the future of our country and I condemn it in the strongest possible terms,” Mohamud said in a statement.
UNICEF Executive Director Anthony Lake said: “The horrific attack on our UNICEF colleagues today in northern Somalia is an assault not only on them but on the people they served. Our immediate thoughts are with the families of the four staff members who were killed and with those who were injured. All of us at UNICEF are deeply saddened, and deeply angered.
“Our colleagues dedicated their lives to working for the children of Somalia. They are not victims. They and those who were wounded are heroes. We mourn their loss and hope for the full recovery of the injured, ” added Lake.
U.N. Secretary-General Ban Ki-moon is reported to have said that “the men and women who bring humanitarian action to light are an inspiration to us all.”
“Targeting such brave and dedicated individuals for violence is an attack on us all,” he said. “We must do our utmost to bring the perpetrators to justice and to ensure that humanitarian personnel have the security they need to carry out their vital role.”