HANOI In his seven years at sea, Afrizal had never been attacked by pirates - until one night late last month.

Armed attackers stole aboard the tugboat Atlantic 3 in Indonesian waters near Singapore on April 27, Afrizal and his captain told AFP, in what an analyst said was part of an upsurge of attacks in that area.

“All of us were tied up and put in a room,” said Afrizal, 40, a native of Indonesia's Sumatra, who uses only one name. “Our eyes were covered.” The room became their cell for several days, until they were cast adrift in a life raft, he said.

Afrizal, one of six Indonesian and two Malaysian crewmen, said they wondered if they would be killed.

“We were very afraid,” he said from Vung Tau in southern Vietnam, after the crew were rescued by the Vietnamese navy.

Myint Shwe, the tug's Myanmar captain, said the drama began after they took on fuel in southern Malaysia's Johor state. The 300-tonne Malaysian-registered tug was towing an empty barge from Thailand to Indonesia, he said.

About 35 nautical miles into their journey from Johor, they were boarded by the seven pirates, Myint Shwe said.

“We did not see their boat. It was night time,” said the 55-year-old skipper.

He and Afrizal said the robbers, armed with a gun and machete, spoke Indonesian and Malaysian.

They stole money and personal items including shoes and socks, leaving the men with only the clothes on their backs, they said.

“They took everything,” Afrizal said.

But their captors brought them food and the occasional cigarette, and allowed them out of the room for toilet breaks.

Freedom eventually came but with it, more fear, Afrizal said - they were cast adrift at night in a rubber raft.

Their drama finally ended the next day, May 3, when a vessel from the Vietnamese navy spotted them under clear skies.

“We were extremely happy we got help,” said Afrizal.

ReCAAP, a Singapore-based international piracy monitoring agency, said the navy responded to a distress signal from the life raft.

“The crew was reported to be in a state of fatigue, but overall well,” the agency said.

Initial investigation indicates the sailors were set adrift near the Spratly islands in the South China Sea, said ReCAAP, which aims to enhance cooperation between governments against piracy and armed robbery in Asian waters.

Efforts were still being made to locate the tug and its barge.

While the overall piracy situation in Southeast Asia and the Malacca Strait has improved in recent years, attacks in the area where the Atlantic 3 was boarded have been on the rise recently, according to Sam Bateman, a senior fellow at the S. Rajaratnam School of International Studies in Singapore.

An increased number of tugs and barges ferry sand from neighbouring countries to the city-state through that area, and the tugs make an easier target than larger vessels because they are slow-moving, Bateman said.

ReCAAP said the Atlantic 3 was the third tug reported missing this year.

The Malacca and Singapore Straits are among the world's busiest commercial waterways and were once the global hotspot for pirate attacks.

Security has improved substantially in recent years, partly thanks to coordinated patrols by nations bordering the waterway.—AFP