Global piracy has fallen by almost a third in the first quarter of the year, while attacks in west African waters are intensifying and and Somali piracy is becoming more violent, a maritime watchdog said.
The International Maritime Bureau (IMB) said the number of pirate attacks across the world fell by almost 28 percent during the first three months of 2012, with 102 attacks reported compared to 142 during the same period last year.
"The reduction in overall attacks is primarily attributed to the disruptive actions and pre-emptive strikes by the navies in the region," the IMB told Reuters. "This emphasises the importance of the navies in deterring and combating Somali piracy."
Somali pirates were still responsible for nearly half the attacks that took place in the first quarter of 2012, according to the report.
The IMB warned that despite the decrease in global attacks, piracy - violent hijackings, robberies and kidnappings for ransom - has intensified and become more violent along the eastern and western coasts of Africa.
Somali pirates, who operate in the Gulf of Aden off the east coast of Africa, and in the Indian Ocean, are suspected of holding 15 vessels and 250 crew members at sea and up to 50 crew members as hostages on land.
"Somali pirates are dangerous and are prepared to fire their automatic weapons and RPGs (rocket-propelled grenades) at vessels in order to stop them," the IMB said.
"There is no evidence to suggest that the danger from Somali piracy is likely to go away in the short to medium term unless further actions are taken against this criminal phenomenon," it said.
There have also been violent attacks off the Nigerian coast.
"In the west coast of Africa we have seen some very violent attacks, including two murders of seafarers on board their ships," IMB director Pottengal Mukundan told ABC.
"The attacks on the west coast are worrying because it is one of the main oil producing areas of the world and the ships which have been targeted have been oil product tankers," Mukundan said.
"Nigerian piracy is increasing in incidence and extending in range," he added. "While the number of reported incidents in Nigeria is still less than Somalia, and hijacked vessels are under control of the pirates for days rather than months, the level of violence against crew is dangerously high."
Other areas where attacks are increasing include the Indonesian archipelago, where small-time and seafaring bandits tend to operate.