LONDON (Reuters) - Pirate attacks around South American and Caribbean waters are growing, and violence is increasingly used during robberies committed on vessels at anchor, a report showed on Wednesday.

The Oceans Beyond Piracy (OBP) non-profit group recorded 71 incidents in Latin America and the Caribbean in 2017, a 163 percent increase over 2016.

OBP said the majority of the attacks occurred in territorial waters, with around 59 percent of incidents involving robbery on yachts. Anchorages in Venezuela, Saint Vincent and the Grenadines, Colombia and St. Lucia were the regional hot spots during 2017, it said.

“We have observed a significant increase in violent incidents and anchorage crime, particularly in the anchorages of Venezuela and the recent violent incidents off Suriname in the first part of this year,” said the report’s lead author Maisie Pigeon.

In late April a pirate attack off the coast of Suriname left at least a dozen fishermen from neighboring Guyana missing and feared dead with three separate bodies found in what was described by Guyana’s President David Granger as a “massacre”.

In a separate incident in May a fishing boat captain was shot dead after his vessel was attacked off Suriname while the rest of the crew survived.

OBP could not give a total economic cost for attacks in Latin America and the Caribbean, but said ship stores and crew belongings reported stolen were estimated to have totaled nearly $1 million in 2017.

The cost of piracy in East Africa reached $1.4 billion in 2017, down from $1.7 billion in 2016 and $7 billion in 2010 during the peak of attacks by Somali gangs.

Since then, the presence of international naval forces, the deployment of private armed guards on board vessels and defensive measures by ship captains has curbed activity.

OBP said there were 54 incidents in 2017 versus 27 in 2016 after a surge of attacks in the first quarter of 2017.

“There are now a wide range of threats to shipping near the Horn of Africa that have been complicated by the conflict and instability in Yemen,” said Phil Belcher, marine director with association INTERTANKO, which represents the majority of the world’s tanker fleet.

Piracy risks remained elevated in West African waters, with 97 incidents recorded in 2017 versus 95 in 2016, with the total cost estimated at $818.1 million in 2017 versus $793.7 million, OBP said.

“Kidnap-for-ransom continues to plague the region, which is a trend that has unfortunately continued from 2016,” OBP’s Pigeon said.