Pirates have so far this year hijacked 13 vessels in Asian waters.

Compare this to last year, where there were only three reported cases, so this is a worrying trend, said Mr Noel Choong of the International Maritime Bureau (IMB).

A violent attack occurred in the South China Sea on Dec 7 when armed pirates boarded a Vietnamese-registered tanker, robbed its crew and killed a sailor.

…Should ships plying regional waters be worried? Maybe not, Dr Sam Bateman of the S. Rajaratnam School of International Studies maintained.

His paper, titled “Piracy in Southeast Asia — The Current Situation”, argues that numbers are inflated when “a very minor incident of petty theft from a ship at anchor counts as one attack equivalent to a major incident”.