Bangkok: A bill imposing civil liabilities on shipowners who cause oil spills and damage the marine ecology was passed by the National Legislative Assembly (NLA) on Thursday.

The bill also requires both Thai and international ships with a freight capacity of more than 2,000 tonnes, that travel in Thai territorial waters to prove they have a sufficient financial guarantee or insurance to cover possible damage they might cause in the event of an oil spill.

Between 1973 and 2011, there were some 215 oil leaks in Thai waters.