Nigerian police on Tuesday announced the arrest of 11 members of a "daredevil" gang after the kidnapping of a senior Sierra Leone diplomat to Abuja last month.
The men are alleged to be part of a "kidnapping gang" that on June 30 seized Alfred Nelson-Williams, Sierra Leone's defence attaché and deputy head of the country's mission in Nigeria. He was released on July 5.
Police said the "daredevil criminal gang" also kidnapped an executive director of the Dangote Group, one of the continent's largest companies.
The kidnappers mounted "road blocks on highways in military uniforms" to capture victims and relocated "from one point to another in the forest with their victims to avoid detection and arrest", police said.
Nelson-Williams said he had been stopped at a checkpoint by men armed with AK-47 assault rifles and dressed in military fatigues while travelling to Kaduna, 200km north of Abuja.
His abduction was the first of a Sierra Leone diplomat anywhere in the world since the country gained independence in 1961, according to foreign ministry sources in Freetown.
Nigeria has long been plagued by kidnappings for ransom where wealthy locals and expatriate workers have been seized and usually returned after payment several days or weeks later.
In the past, kidnapping happened more frequently in the oil-producing south, but the phenomenon has spread to the country's north, with criminal gangs breaking into the lucrative kidnapping trade.