A salvage firm has successfully raised a sunken tour boat to the sea surface off the Shiretoko Peninsula in Japan's northern prefecture of Hokkaido.

The "KAZU I" sightseeing boat sank on April 23 off the peninsula with 26 people on board. Fourteen have been confirmed dead with their bodies recovered, and 12 others remain unaccounted for.

The salvage firm, in its first attempt, lifted the boat from the seabed at a depth of 120 meters to near the surface on Monday.

But the boat sank again to the seabed off Utoro Port in the town of Shari on Tuesday, while it was being towed by a barge. The vessel was later confirmed to be lying on the seabed at a depth of about 180 meters.

In the next attempt, the salvage firm had used an undersea robot to put belts on the boat. From Thursday afternoon, the firm began pulling the vessel up toward the surface. The boat surfaced from the water after 6:50 p.m.

Then, the vessel was fixed to the barge with ropes around 7:10 p.m. The salvage firm is going to tow the boat to shallow waters and lift it onto the barge.

The boat is expected to be unloaded at nearby Abashiri Port.