UN chief remembers 23 killed in Boko Haram suicide car bomb at Nigeria HQ, promises solidarity

U.N. Secretary-General Ban Ki-moon pays tribute to 23 colleagues killed four years ago in a Boko Haram car bombing at his organization's Nigeria headquarters.

Ban is meeting with President Muhammadu Buhari and promises solidarity in the new Nigerian leader's fight against insecurity, unemployment and corruption.

His visit comes as a regional army is preparing a long-delayed offensive against Nigeria's Islamic extremists. The 6-year-old uprising has killed 20,000 people, including more than 1,000 this year.

Ban laid a wreath Monday at the U.N. offices where a suicide car bomber smashed through the barrier and exploded into the reception on Aug. 26, 2011, killing 23 people. He was to meet later Monday with some of the 60 wounded who he said suffered terrible injury and trauma.