Roseline Managbe, an army spokeswoman, said 63 people were detained in a series of raids Wednesday, the Nigerian newspaper BusinessDay reported. She said investigators are unsure whether the kidnappers are after money or have political motives.
Kanene Okonjo was abducted Tuesday from the family's palace in Ogwashi-Uku.
Her husband, who was away at a conference, is the obi, or hereditary ruler of Ogwashi-Uku.
Onyema Okonjo, the couple's oldest son, said he received a phone call from the kidnappers, the Nigerian newspaper Leadership reported. He said they made no ransom demand, wanted to speak to his sister, the finance minister, and apparently mistakenly believed they had called her number.
"They said they are not desperate about money but want to speak with the minister before they will say something"
Okonjo-Iweala, who has degrees from Harvard and the Massachusetts Institute of Technology, is an internationally known economist. She worked for many years at the World Bank, including four years as a managing director, before becoming finance minister last year.