SINGAPORE, Aug 23 — Global shipping industry groups warned oil tankers and freight vessels today to take precautionary measures when travelling in the South China Sea after a recent spike in piracy.

Armed pirates have attacked at least five vessels, including chemical and liquefied natural gas (LNG) tankers, in the last week near the Southeast Asian coast of Pulau Mangkai in Indonesia.

Analysts said vessels in the region were likely to remain vulnerable, but the violence was not expected to disrupt traffic in the key trading route.

“It is possible that more than one group of robbers were involved in the incidents, and they may strike again as they could still be lurking in the area,” said regional government security agency ReCAAP.

Analysts say piracy in the South China Sea has increased in recent years, accounting for around 16 per cent of worldwide sea attacks so far this month.

But the attacks, which usually involve gangs robbing crew members of their cash and personal belongings, are minor compared to other regions.

“Unless there is a clampdown then the illicit trade may continue to expand unabated,” said John Drake, a risk consultant with security and risk mitigation firm AKE Ltd.

“However, the activity is never likely to match levels seen in the Gulf of Aden and Indian Ocean.”

Drake said maritime insurance premiums could increase for vessels travelling in the South China Sea if the attacks begin to involve hostage taking and ship seizures. — Reuters