Military authorities said yesterday that soldiers had arrested 63 people in Delta State during raids aimed at finding the finance minister's 82-year-old mother, Prof Kanene Okonjo, who was kidnapped from her home on Sunday.
It is not yet known whether the abduction of Ngozi Okonjo-Iweala's mother is for political or financial gain.
"Yesterday, the Four Brigade raided Ogwashi-Ukwu in search of Mama," army spokeswoman Roseline Managbe told Reuters, adding that "those arrested are being questioned."
Criminal gangs regularly kidnap people for ransom in Nigeria, but it is rare for them to target members of the political elite.
Two policemen were also arrested this week on suspicion of aiding the kidnappers of Okonjo.
Managbe said two Lebanese men working for Nigerian construction company Setraco had been abducted on Tuesday in Delta State by gunmen who killed a soldier assigned to protect them.
The finance minister, a campaigner against corruption, has received threats in the past, her special adviser Paul Nwabuikwu said on Sunday.
CP advises monarchs to fortify palaces
The commissioner of police in Delta State, Mr. Ikechukwu Aduba, yesterday advised monarchs to engage palace guards to fortify their palaces.
Aduba, who gave the advice when he paraded 25 suspected kidnapers and armed robbers in Asaba, said that the suspects were arrested this week..
He said that the kidnap of Mrs Kanene Okonjo had further reinforced the need for the monarchs to make use of their guards.
Aduba decried the situation where monarchs' palaces were easily accessed by just anybody, saying that it exposed the monarchs to risk.
According to him, "the palace should be fortified and the job of the police is to complement the security. If you have a palace, you are supposed to have your guards and not to rely solely on police security.
"Palace guards are very necessary. Security is everybody's business and if you talk about the vigilance group, they are under the monarchs."