She urged the president to take measures to assure Nigerians that the government cares about the people's welfare.
The bodies of the victims were recovered from two separate shipwrecks, 23 from one and three from the other, with most of them reported to be teenagers aged between 14 to 18.
The former minister took to her Twitter account (@obyezeks), on Wednesday, November 8, 2017, to describe the president's personal silence over the tragedy as a "callous" act.
She urged the president to take measures to assure Nigerians that the government cares about the people's welfare by displaying good leadership.
She posted, "Shocking that you (President Buhari) personally have not acknowledged that 26 of the citizens that you are their president drowned in the Mediterranean Sea and the whole world is talking about it. This is not leadership, sir.
"It is callous for any leadership to never feel the pains that tragedies bring the way of a people. Can your Federal Government signal to the Nigerian Public that Nigerian citizens' lives matter? Can you?
"I recall our public outrage when during the previous administration, then President rather than acknowledge deaths in a bomb blast tragedy was busy at a campaign ground. This Federal Government of President Buhari now repeats same with our 26 girls that drowned in Mediterranean Sea. What changed?"
Earlier on Wednesday, former Vice President Atiku Abubakar called on the government to create more jobs to discourage Nigerians from fleeing abroad for better opportunities.
He posted on his Twitter account (@atiku), "Deeply saddened by the death of 26 Nigerian girls in the Mediterranean. I pray for strength for their families. We must get desperate about creating more jobs, so our young people are not forced to run away from their own country."
According to a report by La Repubblica, most of the 375 survivors of the shipwrecks were sub-Saharan Africans, from Nigeria, Senegal, Ghana, The Gambia and Sudan, with 90 women - eight of them pregnant - and 52 children.
One of the survivors, 23-year-old Dora Omoruyi from Edo State, said she embarked on the journey because she saw no future for herself in Nigeria.
"I wanted to reach Italy. I don't know what to do now. I see no future in Nigeria, there are no jobs."
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Italian authorities have already arrested two men in connection to the heinous crime. The two men, named as Al Mabrouc Wisam Harar, from Libya, and Egyptian Mohamed Ali Al Bouzid, have been charged by investigators after they were identified by survivors as the captains of one of the boats where the victims were killed.