The last young backpackers flew away from Machu Picchu as clouds closed in again, leaving Peru to grapple with flood damage that will close its top tourist site for weeks, or perhaps months.

Spain has returned 45 allegedly contraband pre-Columbian artefacts to Peru during a visit by King Juan Carlos and Queen Sofia.

A top US University is holding some 40,000 artifacts from the famed Inca citadel of Machu Picchu, a Peruvian government official heading efforts to return the pieces said.

Panamanian authorities have announced the discovery of a second ship believed to possibly belong to the fleet Christopher Columbus used on his last voyage to America in the 16th century.