US and Australian aircraft have joined the search for passengers of a missing ferry off Kiribati, as rescuers scoured the central Pacific Ocean for a life raft believed to be carrying survivors.
Eight people rescued from a drifting dinghy on the weekend said the ferry broke up soon after setting out on January 18 and that they had seen other passengers scramble aboard a life raft.
"There is definitely a possibility that the people in the life raft are alive given that only a short while ago we found people in an open dinghy alive," said New Zealand-based rescue coordinator Paul Craven.
"We're hoping in a life raft they're actually in a better survival situation so that's why we've got such an intensive search going today," he said on Tuesday.
Authorities are uncertain how many people had been on board the ferry, Craven told Radio New Zealand. Reports from survivors and government officials varied between 35 and 100 people.
The 17-metre catamaran was reported missing on January 20, two days after it departed Nonouti Island on a 250km trip to Betio in Kiribati.
Australia has sent a P-3 Orion surveillance aircraft to assist in the search and the US Coastguard has sent a Hercules aircraft from Hawaii to scour the northern part of the search area.
A New Zealand aircraft spotted a dinghy on Sunday with eight people, including a 14-year-old girl, who had been adrift for days without water. The eight were rescued by a fishing vessel.
They told rescuers they had scrambled into their tiny dinghy as the ferry disintegrated soon after setting off and that other passengers had made it into another dinghy and a liferaft.
The second dinghy had broken up and likely sunk, Craven said, with the search now focusing on finding the life raft.
He said the rescuers' main concern was that any survivors would be facing the heat for days without drinking water.