Kidnappers in Nigeria's Niger Delta region released three Dutch nationals held since May 4, Anka Mustapha, a spokesman for Bayelsa state's Joint Task Force, which includes the military and police, told Reuters on Saturday.
The kidnapping of expatriates by armed gangs seeking ransom money has been rife in the oil-producing Delta region, although it has tailed off since a 2009 amnesty was signed with militant groups there. Foreign companies have also improved their security.
"Yes they have been rescued (released) and handed over to their country's ambassador," Mustapha said. He declined to give further details.
Nigeria has Africa's largest population and it has become the biggest economy on the continent, overtaking South Africa.
It ranks as one of the worst countries in the world for kidnapping, a multimillion-dollar criminal enterprise. Abductions occur most frequently in the southern oil states, but sometimes in Lagos and the southwest as well.
Last month, Islamist rebels in the northeast kidnapped more than 200 schoolgirls in an attack that has stirred global outrage.