DOUALA, March 19 (Reuters) - Gunmen killed up to nine people and stole an undisclosed sum of money in an overnight raid on banks in Cameroon's port town of Douala, a security source and local media said on Saturday.
Cameroon is one of a number of oil-producing nations in the Gulf of Guinea region that has been plagued by attacks on ships and seaside towns that are often blamed on pirates.
"We suspect the pirates came on swift boats, parked the boats somewhere in the creeks and walked to Bonaberi (a district in the west of Douala) to carry out the attacks," the security source, who asked not to be named, told Reuters.
"They were about 25 in number and wearing T-shirts on which was written "Delta", he added, saying that security forces were currently combing the nearby Wouri river for the assailants.
Those killed included members of a security firm tasked with protecting the banks as well as passengers of a bus and a man on a motorcycle, the source said.
Independent Douala-based Equinox radio-television station confirmed the deaths during the attack but could not say how much money was stolen from the branches of Ecobank and First Trust Bank, which were attacked.
State radio put the death toll at five.
Eight other people were injured in the attack, the security source said.
The Gulf of Guinea region produces more than three million barrels of oil per day and while piracy is not on the scale seen off Somalia, on the east coast of Africa, there are fears it is on the rise and nations are poorly equipped to handle the threat. (Reporting by Tansa Musa; writing by David Lewis; editing by Andrew Roche)