"Pirates armed with automatic weapons in two small boats fired upon and boarded a drifting chemical tanker," the International Maritime Bureau said on its website of the incident on Sunday.
"Crew retreated into the citadel and remained there for the entire night. The crew emerged from the citadel the next day and, upon inspection, found that ship cash was stolen."
The coast of
Benin, which neighbours Nigeria, Africa 's largest oil producer, has seen at least 20 piracy incidents this year compared with none last year. Piracy has long been a problem off . Nigeria