Two Croats, one Montenegrin released in Nigeria

Two Croats, one Montenegrin released in Nigeria

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

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.