LAGOS, Nigeria (AP) — A spokesman says five Indian sailors kidnapped last month off of Nigeria's oil-rich southern delta have been released.

The men had been held since their ship, the SP Brussels, was attacked on Dec. 17 near the Niger Delta.

A statement released Saturday by Martin Baxendale on behalf of Medallion Marine, the ship's operator, said the men were in good health. It did not say whether a ransom had been paid for their release, though that is often the case.

Attacks remain common around the Niger Delta, where foreign oil companies have pumped crude for more than 50 years.