A gang of Somali pirates has left a Japanese chemical tanker they hijacked six weeks ago, freeing its crew and ending a stand-off with US navy ships.
Piracy is a major problem for shipping off Somalia
The pirates ended their occupation of the vessel just days after demanding a $1m (£500,000) ransom.
It is not known why the gang gave up the tanker, or whether the ransom demand was met.
The Golden Nori, which was carrying the highly flammable substance benzene, was hijacked in late October.
It had been sailing from Singapore to Israel when it was attacked.
Her distress calls were picked up by US warships patrolling off the coast of Somalia who fired on the pirates' speedboats, sinking two.
The warships followed the kidnapped chemical tanker into Somali coastal waters and trapped the Golden Nori close to the port of Bossaso, preventing supplies from getting to the ship.
The pirates issued their ransom demand earlier this week, threatening to kill the 23-man crew if their request was not met.
But the US Navy confirmed that the pirates had left the ship overnight.
"All the pirates are off the ship, and the first indication is that all crew members are unharmed," US Navy spokesman Lt John Gay said.
The crew was made up of sailors from Burma, Philippines and South Korea - and officials from those countries and Japan expressed relief that the crisis had come to an end.
Correspondents say Somali coastal waters are now considered to be among the most hazardous in the world. With no effective government, pirates are able to operate largely unchecked.
The US and French navies have been trying to tackle the problem by carrying out patrols.
Reports say this is the first time in nearly a year that no hijacked ships are being held by Somali pirates.