Pirates kidnap two US sailors off Nigerian coast: Sources

ABUJA/LONDON (Reuters) - Armed pirates have attacked an oil supply vessel off the Nigerian coast and kidnapped the captain and chief engineer, both United States citizens, security sources said on Thursday.

The US-flagged, Edison Chouest-owned C-Retriever was attacked in the early hours of Wednesday, British-based security company AKE and two security sources said. The company was not immediately available for comment.

Piracy in the Gulf of Guinea region, which includes Africa's No. 1 oil producer Nigeria and is a significant source of cocoa and metals for world markets, is increasing costs for shipping companies operating there.