Nigeria's President Goodluck Jonathan has visited the site of a deadly bombing in the capital Abuja after cutting short an African Union engagement to meet victims of the attack blamed on Boko Haram.
Jonathan visited the Emab Plaza in central Abuja on Friday where a bomb blast killed at least 21 people on Wednesday and later went to a hospital where victims were being treated, describing the worsening Islamist insurgency as "one of the darkest phases in the history" of Nigeria.
"Nigerians are struggling, thinking about how to contribute to (the) nation's development and working very hard to take care of their families (while) others are busy to kill people," he told reporters outside the hospital.
"It is regrettable," he added. "But surely we will get over it."
Jonathan had planned to attend the second day of talks at the ongoing summit in Equatorial Guinea, but reportedly left the conference on Thursday to return to Abuja.
It was the third major attack in Nigeria's capital since mid-April and raised further fears about Boko Haram's growing strength.
Analysts said the insurgents now appeared capable of attacking wherever they want, including remote villages in their northeastern stronghold, and popular commercial targets near the parliament.
Jonathan, fiercely criticised by many for his handling of the crisis, is widely expected to seek re-election in February, although some in his Peoples Democratic Party have urged him to stand aside.
