Hostage takers released three European captives Monday in Nigeria's restive oil region, officials said.

The two Croatians and one Montenegrin seized Feb. 18 in Port Harcourt were in good health after their release to state officials, said a top security official, who spoke on condition of anonymity due to prohibitions on dealings with media.

The official did not say whether a ransom had been paid.

The Croatian Foreign Ministry confirmed the release.

"The released are feeling fine. After routine medical checkups in a local clinic, they will return to their families with a first possible flight," said the ministry spokesman, Zeljko Belaj.

Scores of foreign workers have been seized in the Niger Delta since the beginning of the year. Hostages are generally released unharmed after a cash payment, although casualties have occurred when kidnappers encountered government forces that patrol the vast region of swamps and creeks.

Over a year of attacks on a maze of oil infrastructure and the workers servicing it have cut Nigeria's daily output by nearly a quarter, helping to push crude prices to record highs in international markets.

Despite generating tens of billions of dollars in oil revenues every year, most of the region's people are mired in deep poverty and abductions for ransom have become common.

Kidnappings and violence have risen ahead of April's general elections. Armed gangs also work as political enforcers for local politicians.

Nigeria is Africa's largest oil exporter and the fifth-largest supplier of crude to the United States.

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