Abuja: Nigerian`s security service on Sunday offered a 25 million naira (USD 160,000 /EUR 116,000) reward for information on the "mastermind" of the August 26 bombing of UN building in Abuja that killed 23 people.
"A reward of 25 million naira is being offered for information that could lead directly to the apprehension or conviction of Mamman Nur ... identified as the mastermind" of the attack, the State Security Service (SSS) said.
"Following the bombing of the UN building ... by Boko Haram, Mammman Nur was identified as the mastermind and security agencies subsequently declared him wanted," the SSS said in the statement.
The SSS text requested members of the public to give any information on the suspect to the nearest police station, military formation or any other security agency.
The SSS attached the photograph of Nur to the e-mail statement.
"He is still declared wanted," said the statement signed by the SSS spokeswoman, Marilyn Ogar.
A suicide bomber on August 26 made his way through a gauntlet of security at the UN`s main compound in the Nigerian capital Abuja, forcing his way through the gate before ramming into the building.
The resulting explosion blew out the building`s first two floors, killing 23 people and leaving 116 others wounded, some seriously.
It was one of the bloodiest attacks targeting the UN.
Radical Islamist Boko Haram sect has claimed responsibility for the attack, condemned by the UN Secretary General Ban Ki-moon.
"This terrorist attack showed utter disregard for human life," Ban said in a message read by his top representative in Nigeria, Daouda Toure.
"It was an assault not just on our premises, but on our values and our work. There can be no justification for such wanton killing and destruction."
The SSS had earlier said that an al Qaeda-linked suspect who recently returned from Somalia masterminded the attack.
A memorial service was held on Thursday in front of the heavily damaged UN building, attended by more than 1,000 people, including Nigerian government and military officials, UN personnel, diplomats, families of the deceased and religious leaders.
Nigerian President Goodluck Jonathan will hold talks with several world leaders on the sidelines of the 66th session of the UN General Assembly this week in New York, his office said in a statement on Sunday.
Jonathan will deliver his statement to the General Assembly on Wednesday and "confer with several world leaders on the strengthening of bilateral relations between Nigeria and their countries", it said.