A maritime watchdog issued a piracy warning to ships in the South China Sea on Wednesday after a sharp increase in attacks with six incidents in as many days.
The International Maritime Bureau (IMB) piracy reporting centre, based in Kuala Lumpur, said the attacks occurred in the South China Sea off the Indonesian islands of Mangkai, Anambas and Natuna.
The South China Sea is situated near the Malacca Straits, a key shipping lane for world trade which more than 50,000 merchant ships ply every year.
The IMB warning advised ships to exercise caution in the area and noted that attacks were still continuing.
"A lot of industry players are concerned that if you don't contain the attacks now then it may come to a point where it may become very hard to control," said Noel Choong, head of the IMB piracy reporting centre.
Choong said that since June 10, pirates have attacked a Malaysian products tanker, a South Korean cargo ship, two Singapore container ships, a Chinese products tanker and a Cyprus container ship.
The most recent incident took place on Wednesday when six armed pirates boarded a Singaporean container ship, stole cash and took hostages before escaping.
Choong said the attacks were mainly in Indonesian waters and urged the country to beef up patrols.
The IMB, in its 2010 first quarter report, said that while there were no incidents recorded in the Malacca Straits from January to March, Indonesia saw its highest number of first quarter incidents in two years, with six boardings recorded.
