LONDON: Pirates working off the coast of Somalia are simply moving farther offshore to escape international naval forces on patrol to contain them, experts say.

Gunmen on Monday launched their longest range hijack attempt yet by opening fire on a big Hong Kong-flagged crude oil tanker, the BW Lion, about 1,000 nautical miles east of Mogadishu, the European Union naval force EU Navfor said.

That bid - a strike deep in the Indian Ocean - failed, but it was a stark demonstration of seaborne gangs' ambition to outwit the naval forces deployed against them and defeat a more determined defense by their civilian prey.