Armed pirates robbed a petroleum products tanker near Ivory Coast's port of Abidjan, a maritime agency and a private security advisor said on Wednesday, in an indication of the increasing mobility of Nigeria-based gangs.
The raid on the tanker came just a day after two failed pirate attacks that occurred just hours apart in waters off Nigeria's southeastern coast, according to the same sources.
Pirate attacks in West Africa's Gulf of Guinea, a significant source of oil, cocoa and metals for world markets, have almost doubled from last year, jacking up insurance costs for shipping companies.
The vast majority of the region's maritime robberies and hijackings are believed to be carried out by criminal gangs based in Nigeria, and the security advisor said this was likely the case with the three incidents last week.
According to the International Maritime Bureau (IMB), a piracy watchdog, the attack occurred at 9.15 p.m. (2115 GMT) on Aug. 27 around 45 nautical miles southeast of Abidjan, one of West Africa's busiest commercial ports.
"Twelve armed pirates with guns boarded a drifting product tanker. They took hostage all crew members, stole ship's cash, crew cash and personal effects and escaped," the IMB report stated.
The attackers destroyed the vessel's navigation equipment before leaving the ship, but no crew were injured and the tanker was not damaged.
A private security advisor who monitors West African piracy confirmed the attack, however a senior Ivorian maritime security official said he was not aware of the incident.
The first known hijacking of a vessel in Ivory Coast's territorial waters occurred late in 2012. Similar attacks were reported in the months that followed, but there has not been a successful hijacking off Ivory Coast in over a year, maritime officials there said.
The country's defence minister said earlier this year it was adding around 40 new vessels to its depleted navy to confront an increase of criminal activity off its coast. Some of those ships, including a 33-metre French-built patrol boat, have already entered into service.
Unlike along the Horn of Africa, however, international navies are not actively engaged in counter-piracy missions in the threatened regional waters off Nigeria, Benin, Togo, Ghana and Ivory Coast.
Reporting by Joe Brock