Rescuers have found a dinghy containing seven survivors while searching for a ferry carrying 50 people that went missing in the waters off Kiribati.

The New Zealand defence force said the crew on a military Orion plane used radar to locate the dinghy. It took them two hours to find the five-metre craft adrift in the Pacific Ocean with seven people, including an unconscious baby, on board.

NEWS || The @NZAirForce P-3K2 Orion has found seven survivors from a ferry with 50 people on board that was reported missing in Kiribati a week ago. MORE: https://t.co/eAQJGM14Ul.#Force4Good pic.twitter.com/p3UimMmGAx — Royal NZ Air Force (@NZAirForce) January 28, 2018

The survivors had scrambled onto the small wooden dinghy after the ferry sank, according to authorities.

The Orion dropped supplies to the survivors including food, water and a radio, New Zealand Defence Force air commodore Darryn Webb said.

The survivors used the radio to tell rescuers they’d managed to get off the ferry when it capsized and climb aboard the dinghy, he said.

Webb said the survivors had very little time to react and found themselves adrift without water or an engine. He said they did have a blanket or tarpaulin which they may have been able to use to get some relief from the sun.

Webb said a fishing boat had changed its course and picked up the survivors on Sunday afternoon. He said the dinghy was drifting more than 180km (112 miles) from the nearest major island when it was found.

“Our heart goes out to the baby and to all those remaining of the 50-plus people,” he said.

Webb said there was a lot of debris near the dinghy, which may have been from the ferry.

Searchers planned to regroup and interview the survivors before deciding whether to continue the search for the MV Butiraoi and its remaining passengers.

The ferry failed to arrive at its destination more than a week ago, but the fact that it was missing was only reported on Friday. Questions remain as to why it took Kiribati authorities so long to tell New Zealand officials the ferry was missing. Webb said a Kiribati plane had earlier searched for the ferry but didn’t have sophisticated radar equipment.

Butiraoi, an inter-island passenger ferry, left Nonouti Island on 18 January for a two-day, 250km trip to Betio, the largest township of Kiribati’s capital city, South Tarawa. The 17-metre wooden catamaran failed to arrive on 20 January.

Local authorities said the boat ran aground and underwent repairs to its propeller shaft before it left Nonouti Island. It has a high frequency radio but it is not known whether it has enough fuel and emergency supplies on board.