A plague of piracy off the Somali coast, with six vessels seized so far this year and many more attacked or threatened, has prompted the UN Security Council to consider a tougher counter-attack by the world’s navies.

The latest victims were the 26 crew of a Spanish fishing boat, freed unharmed at the weekend after a $1.2m (€770,000, £606,000) ransom was paid, according to Somali officials.