U.N. Secretary General Ban Ki-moon says the United Nations will review security threats to its buildings around the world in the wake of last week's bombing of the U.N. headquarters in Nigeria.

Mr. Ban told the U.N. Security Council Tuesday that the international organization will be undertaking a full review of the bombing itself as well as what he called “a global threat review.”

He said that clearly the United Nations and its workers are being targeted more and more often by terrorists.

The secretary general said 11 of the 23 people killed in last Friday's bombing were U.N. staffers.

More than 80 people were also wounded in the attack when a suicide bomber rammed a vehicle through the exit gates of the U.N. compound in Abuja.

A man who identified himself as a spokesman for Boko Haram, a radical Islamic group in Nigeria, told VOA the group is responsible

for the bombing.

Boko Haram has been blamed for many bombings and shootings aimed at authority figures in northeastern Nigeria, mainly in the

state of Borno. The group also has claimed responsibility for other bombings, including the June bombing of Nigeria's national police headquarters in Abuja.

The group wants a strict form of Islamic law applied more widely across Africa's most populous nation.