British seafarers say they want more protection against pirates who, armed with speedboats, guns and grappling hooks, have become especially active off Brazil and the South China Sea.

The International Shipping Federation said Thursday that attacks on merchant ships by pirates and armed robbers are growing more frequent, more sophisticated and more violent.The federation said the waters of the South China Sea and ports on the Brazilian coast are particularly notorious as "piracy black spots."

A spokesman for National Union of Marine, Aviation and Transport said the union recently visited the Brazilian Embassy in London to ask the ambassador to beef up security at Brazil's ports and seas.