President Goodluck Jonathan has visited Emab Plaza in central Abuja where a bomb blast killed at least 21 people on Wednesday - with the attack blamed on Boko Haram.
Jonathan, who reportedly cut short an African Union engagement to meet victims, later went to a hospital where victims were being treated.
He was filled with passion and described 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 killing people,” he told reporters outside the hospital.
“It is regrettable,” he added. “But surely we will get over it.”
It was the third major attack in Nigeria’s capital since mid-April and raised further fears about Boko Haram’s growing strength.