Search teams scanning the Java Sea for the main wreckage from AirAsia flight QZ8501 have found “four large objects”, the search chief says.
Bambang Soelistyo said the biggest of the objects was 18m (59ft) long and he believed they were parts of the plane.
The Airbus A320 vanished with 162 people on board en route from Surabaya in Indonesia to Singapore last Sunday.
So far 30 bodies have been recovered with most of the remaining bodies thought to be trapped in the fuselage.
Indonesia’s weather agency believes bad weather was the “biggest factor” behind the crash, in which no survivors were found.
The BBC’s Rupert Wingfield-Hayes at the forward operating base in Pangkalan Bun says it seems this could be the breakthrough search teams have been hoping for.
The cause of the crash is not yet known. Specialist equipment has arrived to the search for the plane’s “black-box” flight recorders, though officials say no signals have been picked up yet.
Sonar from an Indonesian navy ship detected one large object on Friday night with the other three found on Saturday, Mr Soelistyo announced.
“I am confident these are parts of the missing AirAsia plane,” he said.
According to the Associated Press news agency, he also gave the width of the largest object found, saying it was 5.4m. Another was said to be 10m long.
Mr Soelistyo said an ROV (remotely operated underwater vehicle) was being lowered into the water to get an actual picture of the objects, which were at a depth of 30m.
He warned that the height of waves was hampering the search effort at sea. The waves were four to five metres high, he said.
Another official, Supriyadi, said earlier that poor visibility was hampering the work of the ROVs.